Microelectronic package including microelectronic elements having stub minimization for wirebond assemblies without windows

ABSTRACT

A microelectronic assembly (300) or system (1500) includes at least one microelectronic package (100) having a microelectronic element (130) mounted face up above a first surface (108) of a substrate (102), one or more columns (138, 140) of contacts (132) extending in a first direction (142) along the microelectronic element front face. Columns (104A, 105B, 107A, 107B) of terminals (105 107) exposed at a second surface (110) of the substrate extend in the first direction. First terminals (105) exposed at surface (110) in a central region (112) thereof having width (152) not more than three and one-half times a minimum pitch (150) of the columns of terminals can be configured to carry address information usable to determine an addressable memory location. An axial plane of the microelectronic element can intersect the central region.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.15/168,789, filed May 31, 2016, which is a continuation of U.S.application Ser. No. 14/244,007, filed Apr. 3, 2014, now U.S. Pat. No.9,377,824, which is a continuation of International Application No.PCT/US2012/058273, filed Oct. 1, 2012 and is also a continuation ofInternational Application Nos. PCT/US2012/058398 and PCT/US2012/058407,filed Oct. 2, 2012. International Application No. PCT/US2012/058273 is acontinuation of U.S. application Ser. No. 13/440,313, filed Apr. 5,2012, which application claims the benefit of the filing date of U.S.Provisional Application Nos. 61/600,271 filed Feb. 17, 2012, 61/542,488filed Oct. 3, 2011, 61/542,495 filed Oct. 3, 2011, and 61/542,553 filedOct. 3, 2011. International Application No. PCT/US2012/058398 is acontinuation of U.S. application Ser. No. 13/440,299, filed Apr. 5,2012, which application claims the benefit of the filing date of U.S.Provisional Application Nos. 61/600,271 filed Feb. 17, 2012, 61/542,488filed Oct. 3, 2011, 61/542,495 filed Oct. 3, 2011, and 61/542,553 filedOct. 3, 2011. International Application No. PCT/US2012/058407 is acontinuation of U.S. application Ser. No. 13/440,290, filed Apr. 5,2012, which application claims the benefit of the filing date of U.S.Provisional Application Nos. 61/600,271 filed Feb. 17, 2012, 61/542,488filed Oct. 3, 2011, 61/542,495 filed Oct. 3, 2011, and 61/542,553 filedOct. 3, 2011. The disclosures of all said applications are herebyincorporated herein by reference.

BACKGROUND OF THE INVENTION

The subject matter of the present application relates to microelectronicpackages and assemblies incorporating microelectronic packages.

Semiconductor chips are commonly provided as individual, prepackagedunits. A standard chip has a flat, rectangular body with a large frontface having contacts connected to the internal circuitry of the chip.Each individual chip typically is contained in a package having externalterminals connected to the contacts of the chip. In turn, the terminals,i.e., the external connection points of the package, are configured toelectrically connect to a circuit panel, such as a printed circuitboard. In many conventional designs, the chip package occupies an areaof the circuit panel considerably larger than the area of the chipitself. As used in this disclosure with reference to a flat chip havinga front face, the “area of the chip” should be understood as referringto the area of the front face.

Size is a significant consideration in any physical arrangement ofchips. The demand for more compact physical arrangements of chips hasbecome even more intense with the rapid progress of portable electronicdevices. Merely by way of example, devices commonly referred to as“smart phones” integrate the functions of a cellular telephone withpowerful data processors, memory and ancillary devices such as globalpositioning system receivers, electronic cameras, and local area networkconnections along with high-resolution displays and associated imageprocessing chips. Such devices can provide capabilities such as fullinternet connectivity, entertainment including full-resolution video,navigation, electronic banking and more, all in a pocket-size device.Complex portable devices require packing numerous chips into a smallspace. Moreover, some of the chips have many input and outputconnections, commonly referred to as “I/Os.” These I/Os must beinterconnected with the I/Os of other chips. The components which formthe interconnections should not greatly increase the size of theassembly. Similar needs arise in other applications as, for example, indata servers such as those used in internet search engines whereincreased performance and size reduction are needed.

Semiconductor chips containing memory storage arrays, particularlydynamic random access memory chips (DRAMs) and flash memory chips arecommonly packaged in single- or multiple-chip packages and assemblies.Each package has many electrical connections for carrying signals, powerand ground between terminals and the chips therein. The electricalconnections can include different kinds of conductors such as horizontalconductors, e.g., traces, beam leads, etc., which extend in a horizontaldirection relative to a contact-bearing surface of a chip, verticalconductors such as vias, which extend in a vertical direction relativeto the surface of the chip, and wire bonds which extend in bothhorizontal and vertical directions relative to the surface of the chip.

Conventional microelectronic packages can incorporate a microelectronicelement which is configured to predominantly provide memory storagearray function, i.e., a microelectronic element that embodies a greaternumber of active devices to provide memory storage array function thanany other function. The microelectronic element may be or include a DRAMchip, or a stacked electrically interconnected assembly of suchsemiconductor chips. Typically, all of the terminals of such package areplaced in sets of columns adjacent to one or more peripheral edges of apackage substrate to which the microelectronic element is mounted.

For example, in one conventional microelectronic package 12 seen in FIG.1, three columns 14 of terminals can be disposed adjacent a firstperipheral edge 16 of the package substrate 20 and three other columns18 of terminals can be disposed adjacent a second peripheral edge 22 ofthe package substrate 20. A central region 24 of the package substrate20 in the conventional package does not have any columns of terminals.FIG. 1 further shows a semiconductor chip 11 within the package havingelement contacts 26 on a face 28 thereof which are electricallyinterconnected with the columns 14, 18 of terminals of the package 12through wire bonds 30 extending through an aperture, e.g., bond window,in the central region 24 of package substrate 20. In some cases, anadhesive layer 32 may be disposed between the face 28 of themicroelectronic element 11 and the substrate 20 to reinforce themechanical connection between the microelectronic element and thesubstrate, with the wire bonds extending through an opening in theadhesive layer 32.

In light of the foregoing, certain improvements in the positioning ofterminals on microelectronic packages can be made in order to improveelectrical performance, particularly in assemblies which include suchpackages and a circuit panel to which such packages can be mounted andelectrically interconnected with one another.

SUMMARY OF THE INVENTION

In accordance with an aspect of the invention, a microelectronic packagecan include a substrate having a first surface, a second surfaceopposite the first surface, and a plurality of substrate contactsexposed at the second surface. The second surface can extend in thefirst direction and in a second direction transverse thereto. Themicroelectronic package includes a microelectronic element having memorystorage array function, the microelectronic element having a rear facefacing the first surface, a front face opposite the first surface, andfirst and second opposed edges each extending between the front and rearfaces and extending in the first direction parallel to the front face.

The microelectronic element can have one or more columns of elementcontacts exposed at the front face, each column extending in the firstdirection along the front face. An axial plane normal to the front facecan intersect the front face along a line extending in the firstdirection and centered relative to the one or more columns of elementcontacts. Conductive structure may extend above the front face. Theconductive structure can electrically connect the element contacts withthe substrate contacts.

The microelectronic package may include a plurality of columns ofterminals extending in the first direction which are exposed at thesecond surface of the substrate and electrically connected with thesubstrate contacts. The terminals can include first terminals exposed atthe second surface in a central region of the second surface of thesubstrate. The first terminals can be configured to carry addressinformation usable by circuitry within the package to determine anaddressable memory location from among all the available addressablememory locations of a memory storage array of the microelectronicelement. The central region can have a width in the second directionwhich is not more than three and one-half times a minimum pitch betweenany two adjacent columns of the parallel columns of the terminals. Theaxial plane can intersect the central region.

In one example, the microelectronic element may embody a greater numberof active devices to provide memory storage array function than anyother function.

In one embodiment, the first terminals can be configured to carry all ofthe address information usable by the circuitry within the package todetermine the addressable memory location in the memory storage array.In a particular example, the first terminals can be configured to carryinformation that controls an operating mode of the microelectronicelement. In one example, the first terminals can be configured to carryall of the command signals transferred to the microelectronic package,the command signals being write enable, row address strobe, and columnaddress strobe signals. In an exemplary embodiment, the first terminalscan be configured to carry clock signals transferred to themicroelectronic package which are clocks usable for sampling signalscarrying the address information. In a particular embodiment, the firstterminals can be configured to carry all of the bank address signalstransferred to the microelectronic package.

In a particular example, the terminals can be configured to connect themicroelectronic package to at least one component external to themicroelectronic package. In one example, the element contacts caninclude redistribution contacts exposed at the front face of themicroelectronic element. Each redistribution contact can be electricallyconnected with a contact pad of the microelectronic element through atleast one of a trace or a via. In one embodiment, the conductivestructure can include wire bonds extending from the element contacts andelectrically connected with the substrate contacts. In an exemplaryembodiment, the first terminals may be arranged in no more than two ofthe columns of terminals. In a particular embodiment, the firstterminals can be arranged in a single one of the columns of terminals.In one example, the first terminals may be arranged in no more than fourof the columns of terminals.

In an exemplary embodiment, the substrate can have first and secondopposed edges between the first and second opposed surfaces. The firstand second edges can extend in the first direction. The second surfacecan have first and second peripheral regions adjacent to the first andsecond edges, respectively. The central region can separate the firstand second peripheral regions. The terminals can include a plurality ofsecond terminals exposed at the second surface in at least one of theperipheral regions. At least some of the second terminals can beconfigured to carry information other than the address information. Inone embodiment, at least some of the second terminals can be configuredto carry data signals. In a particular example, the substrate caninclude a dielectric element having a coefficient of thermal expansion(“CTE”) in the plane of the dielectric element of less than 30 parts permillion per degree Celsius (“ppm/° C.”). In an exemplary embodiment, thesubstrate can include an element having a CTE of less than 12 ppm/° C.

In accordance with another aspect of the invention, a microelectronicpackage can include a substrate having a first surface, a second surfaceopposite the first surface, a plurality of substrate contacts exposed atthe first surface, and a microelectronic element having a rear facefacing the first surface of the substrate, the microelectronic elementhaving memory storage array function. In one example, themicroelectronic element may have a greater number of active devicesconfigured for providing memory storage array function than any otherfunction. Conductive structure, which may extend above the front face,electrically connects the contacts with the substrate contacts. Aplurality of parallel columns of terminals can be exposed at the secondsurface of the substrate and extending in a first direction along thesecond surface, the terminals electrically connected with the substratecontacts. The microelectronic element can have a front face opposite thefront face and facing away from the first surface, and first and secondopposed edges each extending between the front and rear faces andextending in a first direction parallel to the front face. Themicroelectronic element can have at least one column of element contactsextending in the first direction along the front face. The first andsecond edges can define an axial plane extending in the first directionand also in a third direction normal to the rear face of themicroelectronic element. The axial plane can be centered relative to thefirst and second edges.

The terminals can include first terminals exposed at the second surfaceof the substrate in a central region of the second surface. The firstterminals can be configured to carry a majority of the addressinformation usable by circuitry within the package to determine anaddressable memory location from among all the available addressablememory locations of a memory storage array of the microelectronicelement. The central region can have a width in the second direction.The width of the central region may be not more than three and one-halftimes a minimum pitch between any two adjacent columns of the parallelcolumns of the terminals. The axial plane can intersect the centralregion. In one embodiment, the first terminals can be configured tocarry at least three-quarters of the address information usable by thecircuitry within the package to determine the addressable memorylocation in the memory storage array.

In accordance with yet another aspect of the invention, amicroelectronic package can include a substrate having a first surface,a second surface opposite the first surface, a plurality of firstsubstrate contacts exposed at the first surface and a plurality ofsecond substrate contacts exposed at the first surface. Themicroelectronic package can include first and second microelectronicelements each having memory storage array function. In one example, themicroelectronic package can embody a greater number of active devices toprovide memory storage array function than any other function.

The first and second microelectronic elements can be spaced apart fromone another on the first surface, and can have parallel first edges eachextending in the first direction. An axial plane normal to the firstsurface of the substrate can extend in the first direction and can becentered among the first edges. The first and second microelectronicelements can have rear faces facing the first surface, front facesopposite the rear faces, and a plurality of contacts exposed at thefront faces. Conductive structure, which may extend above the frontfaces, can electrically connect the contacts of the first and secondmicroelectronic elements with the first and second substrate contacts,respectively.

A plurality of parallel columns of terminals can be exposed at thesecond surface of the substrate and electrically connected with thefirst and second substrate contacts. The terminals can include firstterminals exposed in a central region of the second surface of thesubstrate. The columns of terminals may extend in the first direction.The first terminals can be configured to carry address informationusable by circuitry within the package to determine an addressablememory location from among all the available addressable memorylocations of a memory storage array within the first and secondmicroelectronic elements. The central region can have a width in thesecond direction. The width of the central region may be not more thanthree and one-half times a minimum pitch between any two adjacentcolumns of the parallel columns of the terminals. The axial plane canintersect the central region.

In one embodiment, the first terminals can be configured to carry all ofthe address information usable by the circuitry within the package todetermine the addressable memory location in the memory storage array.In a particular example, the first terminals can be configured to carryinformation that controls an operating mode of a microelectronic elementof the first and second microelectronic elements. In one example, thefirst terminals can be configured to carry clock signals and all of thecommand signals, address signals, and bank address signals transferredto the microelectronic package, the command signals being write enable,row address strobe, and column address strobe, and the clock signalsbeing clocks used for sampling signals carrying the address information.

In an exemplary embodiment, the front faces of the first and secondmicroelectronic elements can extend in a single plane parallel to thefirst surface of the substrate. In a particular example, the conductivestructure can include wire bonds extending from the contacts of thefirst and second microelectronic elements and electrically connectedwith the respective first and second substrate contacts. In one example,the first terminals may be arranged in no more than four of the columnsof terminals. In one example, the contacts of each of themicroelectronic elements can include redistribution contacts exposed atthe front face of the respective microelectronic element. Eachredistribution contact can be electrically connected with a contact padof the respective microelectronic element through at least one of atrace or a via. At least some of the redistribution contacts can bedisplaced from the contacts of the respective microelectronic element inat least one direction along the front face of the microelectronicelement.

In a particular example, the substrate can have first and second opposededges between the first and second opposed surfaces. The first andsecond edges can extend in the first direction. The second surface canhave first and second peripheral regions adjacent to the first andsecond edges, respectively. The central region can separate the firstand second peripheral regions. The terminals can include a plurality ofsecond terminals exposed at the second surface in at least one of theperipheral regions. At least some of the second terminals can beconfigured to carry information other than the address information. Inone embodiment, at least some of the second terminals can be configuredto carry data signals.

In accordance with still another aspect of the invention, amicroelectronic package can include a substrate having a first surface,a plurality of first substrate contacts exposed at the first surface,and a plurality of second substrate contacts exposed at the firstsurface, the package including first and second microelectronic elementshaving memory storage array function. In one example, eachmicroelectronic element may embody a greater number of active devices toprovide memory storage array function than any other function. Themicroelectronic package includes conductive structure electricallyconnecting the contacts of the microelectronic elements with thesubstrate contacts. In some cases, the conductive structure can extendabove the front face of each microelectronic element, and a plurality ofparallel columns of terminals can be exposed at a second surface of thesubstrate and electrically connected with the first and second substratecontacts. The second surface of the substrate can be opposite the firstsurface. The second surface can extend in a first direction and in asecond direction transverse thereto.

The first and second microelectronic elements can be spaced apart fromone another on the first surface, and can have first parallel edges eachextending in the first direction. An axial plane normal to the firstsurface of the substrate can extend in the first direction and can becentered among the first edges. The first and second microelectronicelements can have rear faces facing the first surface, front facesopposite the rear faces, and a plurality of contacts exposed at thefront faces. The conductive structure can electrically connect thecontacts of the first and second microelectronic elements with the firstand second substrate contacts, respectively.

The terminals can include first terminals exposed a the second surfacein a central region of the second surface of the substrate. The firstterminals can be configured to carry a majority of the addressinformation usable by circuitry within the package to determine anaddressable memory location from among all the available addressablememory locations of a memory storage array of the first and secondmicroelectronic elements. The central region can have a width in thesecond direction. The width of the central region may be not more thanthree and one-half times a minimum pitch between any two adjacentcolumns of the parallel columns of the terminals. The axial plane canintersect the central region. In a particular example, the terminals canbe configured to carry at least three-quarters of the addressinformation usable by the circuitry within the package to determine theaddressable memory location in the memory storage array.

An aspect of the invention provides a microelectronic package comprisinga substrate having a first surface, a second surface opposite the firstsurface, and a plurality of substrate contacts exposed at the secondsurface. A plurality of stacked semiconductor chips may overlie thefirst surface, at least one of the semiconductor chips having a frontface facing away from the first surface, and a plurality of contactsexposed at the front face. At least some of the contacts can be disposedat positions of at least one column thereof extending in a firstdirection along the front face. An axial plane normal to the front faceof the at least one semiconductor chip can extend in the first directionand be centered relative to the at least one column of contacts. Thepackage further includes conductive structure electrically connectingthe contacts with the substrate contacts, which in one example, canextend above the front face of the at least one semiconductor chip.

Terminals exposed at the second surface can be disposed at positionswithin a plurality of parallel columns each extending in the firstdirection. The terminals can be electrically connected with thesubstrate contacts and can include a plurality of first terminalsexposed in a central region of the second surface, the first terminalsconfigured to carry address information usable by circuitry within thepackage to determine an addressable memory location of a memory storagearray of at least one of the stacked semiconductor chips having memorystorage array function,

The central region can have a width in a direction transverse to thesecond direction, the width not more than three and one-half times aminimum pitch between any two adjacent parallel columns of theterminals, wherein the axial plane intersects the central region.

In one example, the microelectronic element may embody a greater numberof active devices configured for providing memory storage array functionthan any other function.

In one example, the at least one semiconductor chip having the frontface facing away from the first surface can be a first semiconductorchip, and the stacked semiconductor chips can include at least onesecond semiconductor chip overlying the front face of the firstsemiconductor chip and electrically interconnected with the firstsemiconductor chip.

In one example, at least one of the first semiconductor chip or the atleast one second semiconductor chip may be configured to perform atleast one of: partially or fully decode information received at acontact thereof, or regenerate information received at the contactthereof for transfer to another of at least one of the firstsemiconductor chip or to another of the at least one secondsemiconductor chip.

In one example, at least some of the first and second semiconductorchips can be electrically connected with one another by a plurality ofthrough-silicon vias.

In one example, at least one of the first semiconductor chip or the atleast one second semiconductor chip can embody a greater number ofactive devices to provide memory storage array function than any otherfunction.

In one example, at least some of the electrical interconnections betweenthe first and second semiconductor chips can be through wire bondsextending between at least some contacts of the first semiconductor chipand at least some contacts exposed at a face of the at least one secondsemiconductor chip which faces away from the first surface.

In one example, the wire bonds may include wire bonds extending from thecontacts adjacent to first and second opposed edges of the at least onesecond semiconductor chip.

In one example, the wire bonds may include wire bonds extending from thecontacts adjacent to a first edge of each of a plurality of the at leastone second semiconductor chips. The second semiconductor chips may havecontact-bearing faces facing away from the front face of the firstsemiconductor chip and can be staggered such that at least some contactsof each second semiconductor chip are exposed beyond the first edge ofeach second semiconductor chip disposed thereabove.

In one example, at least some of the electrical interconnections betweenthe first and second semiconductor chips can be through conductorsdisposed on or within the substrate.

In one example, the at least one second semiconductor chip has contactson a face confronting the front face of the first semiconductor chip.The contacts of the at least one second semiconductor chip can face andbe joined to corresponding contacts on the front face of the firstsemiconductor chip.

In one example, the first semiconductor chip can be configured toregenerate the address information for transfer to the at least onesecond semiconductor chip.

In one example, the first semiconductor chip can be configured to atleast partially decode at least one of address information or commandinformation received at the first terminals for transfer to the at leastone second semiconductor chip.

In one example, the at least one second semiconductor chip can be aplurality of second semiconductor chips electrically interconnected withone another, wherein at least some of the electrical connections betweenthe plurality of second semiconductor chips can be through wire bonds.

In one example, the at least one second semiconductor chip can be aplurality of second semiconductor chips electrically interconnected withone another. In such example, at least some of the electricalconnections between the plurality of second semiconductor chips can bethrough electrically conductive traces extending along at least one edgeof the microelectronic element.

In one example, the at least one second semiconductor chip can be aplurality of second semiconductor chips electrically interconnected withone another by a plurality of through-silicon vias.

In one example, each of the first and second semiconductor chips canembody a greater number of active devices to provide memory storagearray function than any other function.

In one example, the first semiconductor chip can be configured toregenerate at least some of the address information received at thefirst terminals for transfer to each second semiconductor chip, and eachsecond semiconductor chip may be not configured to regenerate theaddress information for transfer to another semiconductor chip of thefirst and second semiconductor chips.

In one example, the first semiconductor chip can be configured to atleast partially decode the address information received at the firstterminals for transfer to each second semiconductor chip, and eachsecond semiconductor chip may be not configured to fully decode theaddress information.

In one example, the first semiconductor chip can be configured to atleast partially decode information received at at least one of the firstterminals for controlling an operating mode of the at least one secondsemiconductor chip.

In one example, the at least one second semiconductor chip may include adynamic random access memory (“DRAM”) storage array.

In one example, the memory storage array function of the at least onesecond semiconductor chip can be implemented in NAND flash, resistiveRAM, phase-change memory, magnetic RAM, static RAM, spin-torque RAM, orcontent-addressable memory technology.

A microelectronic package according to another aspect of the inventioncan include a substrate having first and second opposed surfaces and aplurality of substrate contacts exposed at the first surface. First andsecond microelectronic elements each having memory storage arrayfunction can be spaced apart from one another in a direction along thefirst surface and may have first parallel edges each extending in thefirst direction. An axial plane normal to the first surface may extendin the first direction and can be centered among the first paralleledges. Each microelectronic element may have a front face facing awayfrom the first surface and a plurality of substrate contacts exposed atthe front face. The contacts of each microelectronic element can beelectrically connected with the substrate contacts through conductivestructure.

A plurality of terminals can be exposed at the second surface atpositions within a plurality of parallel columns. The terminals can beelectrically connected with the substrate contacts. The terminals caninclude first terminals exposed in a central region of the secondsurface of the substrate, the first terminals being configured to carryaddress information usable by circuitry within the package to determinean addressable memory location of a memory storage array of themicroelectronic elements.

The central region can have a width in the second direction, the widthof the central region not more than three and one-half times a minimumpitch between any two adjacent columns of the parallel columns of theterminals. The axial plane may intersect the central region.

In one example, each of the microelectronic elements may embody agreater number of active devices to provide memory storage arrayfunction than any other function.

In one example, the first terminals can be configured to carry all ofthe address information usable by the circuitry within the package todetermine the addressable memory location.

In one example, the first terminals can be configured to carryinformation that controls an operating mode of at least one of themicroelectronic elements.

In one example, the first terminals can be configured to carry clocksignals and the command signals, address signals, and bank addresssignals transferred to the microelectronic package, the command signalsbeing write enable, row address strobe, and column address strobe, andthe clock signals being clocks used for sampling signals carrying theaddress information.

In one example, the front faces of each of the microelectronic elementscan extend in a single plane parallel to the first surface of thesubstrate.

In one example, the microelectronic package may further include thirdand fourth microelectronic elements spaced apart from one another in adirection parallel to the first surface. The third and fourthmicroelectronic elements may have front surfaces facing away from thefirst surface and first parallel edges extending in the first directionand a plurality of element contacts exposed at the front surface. Thecontacts of each microelectronic element may include at least one columnthereof extending in the first direction adjacent to at least one of thefirst parallel edges of such microelectronic element. The axial planecan be centered among the first edges of the first, second, third andfourth microelectronic elements.

In one example, the central region can be disposed within an area of thesubstrate beyond which none of the faces of the first, second, third orfourth microelectronic elements extend.

In one example, each of the microelectronic elements may have two firstparallel edges extending in the same direction as the columns ofcontacts on the respective microelectronic element, and two secondparallel edges extending in a direction transverse to the first edge. Aplane containing either first edge of at least one of themicroelectronic elements and normal to the face of such microelectronicelement can intersect the first edge of another of the microelectronicelements.

In accordance with an aspect of the invention, a microelectronicassembly can include a circuit panel having a first surface, a secondsurface opposite the first surface, and panel contacts exposed at eachof the first and second opposed surfaces, and first and secondmicroelectronic packages having terminals mounted to the panel contactsat the first and second surfaces, respectively. The circuit panel canelectrically interconnect at least some terminals of the firstmicroelectronic package with at least some corresponding terminals ofthe second microelectronic package. Each of the first and secondmicroelectronic packages can include a substrate having a first surface,a second surface opposite the first surface, and a plurality ofsubstrate contacts exposed at the first surface. Each package mayinclude a microelectronic element having memory storage array function.In one example, the microelectronic element may include a greater numberof active devices configured for providing memory storage array functionthan any other function. The microelectronic element may have a frontface facing away from the first surface of the substrate and one or morecolumns of element contacts exposed at the front face and extending in afirst direction along the front face, such that an axial plane normal tothe front face extends in the first direction and is centered relativeto the one or more columns of element contacts. Conductive structure,which in some cases may extend above the front face of themicroelectronic element, electrically connects the contacts of themicroelectronic element with the substrate contacts.

A plurality of parallel columns of terminals can extend in the firstdirection, which are exposed at the second surface and electricallyconnected with the substrate contacts. The terminals can include firstterminals exposed in a central region of the second surface of thesubstrate. The first terminals can be configured to carry a majority ofthe address information usable by circuitry within the package todetermine an addressable memory location from among all the availableaddressable memory locations of a memory storage array of themicroelectronic element. The central region in some cases may have awidth in the second direction which is not more than three and one-halftimes a minimum pitch between any two adjacent columns of the parallelcolumns of the terminals, and the axial plane may intersect the centralregion.

In one embodiment, the first terminals of each microelectronic packagecan be configured to carry all of the address information usable by thecircuitry within the respective microelectronic package to determine anaddressable memory location. In a particular example, the firstterminals of each microelectronic package can be configured to carryinformation that controls an operating mode of the microelectronicelement of the respective microelectronic package. In one example, thefirst terminals of each microelectronic package can be configured tocarry all of the command signals transferred to the respectivemicroelectronic package, the command signals being write enable, rowaddress strobe, and column address strobe signals.

In an exemplary embodiment, the first terminals of each microelectronicpackage can be configured to carry clock signals transferred to therespective microelectronic package, the clock signals being clocks usedfor sampling signals carrying the address information. In oneembodiment, the first terminals of each microelectronic package can beconfigured to carry all of the bank address signals transferred to therespective microelectronic package. In an exemplary embodiment, at leastthe first terminals of the first and second microelectronic packages canbe arranged at corresponding positions of grids, respectively. The gridscan be aligned within one ball pitch of one another in x and yorthogonal directions parallel to the first and second circuit panelsurfaces.

In a particular example, the grids can be aligned with one another inthe x and y orthogonal directions such that the terminals of the gridsare coincident with one another. In one embodiment, each position ofeach grid can be occupied by one of the terminals. In an exemplaryembodiment, at least one position of each grid may not be occupied by aterminal. In a particular embodiment, at least half of the positions ofthe grids of the first and second packages can be aligned with oneanother in x and y orthogonal directions parallel to the first surfaceof the circuit panel. In an exemplary embodiment, the grids of the firstand second microelectronic packages can be functionally and mechanicallymatched. In one example, a length of a stub of at least one ofelectrical connections between one of the first terminals of the firstmicroelectronic package and a corresponding one of the first terminalsof the second microelectronic package can be less than seven times aminimum pitch of the first terminals of each of the microelectronicpackages.

In an exemplary embodiment, at least some of the electrical connectionsthrough the circuit panel between the first terminals of the first andsecond microelectronic packages can have an electrical length ofapproximately a thickness of the circuit panel. In a particular example,the signal assignments of the first terminals can be the same on each ofthe first and second packages. The first terminals on each of the firstand second packages can be disposed at positions within first and secondcolumns of terminals. The first column of terminals of the first packagecan be aligned within one ball pitch in x and y orthogonal directionswith the second column of terminals of the second package. The secondcolumn of terminals of the first package can be aligned within one ballpitch in x and y orthogonal directions with the first column ofterminals of the second package.

In one example, the total combined length of the conductive elementsconnecting a pair of electrically coupled first and second panelcontacts exposed at the first and second surfaces of the circuit panelcan be less than seven times a smallest pitch of the panel contacts. Inone embodiment, the circuit panel can include a bus having a pluralityof conductors configured to carry all of the address informationtransferred to each of the microelectronic packages. The conductors canextend in a direction parallel to the first and second surfaces.

In an exemplary embodiment, the first terminals of each microelectronicpackage can be disposed at positions within a single column of terminalsof the respective microelectronic package. The circuit panel may includeno more than one routing layer for routing of the address informationbetween a connection site on the circuit panel at which the terminals ofthe first and second microelectronic packages are electrically connectedand a different connection site at which the terminals of at least athird microelectronic package are electrically connected.

In a particular embodiment, the first terminals of each microelectronicpackage may be disposed at positions within no more than two parallelcolumns of terminals of the respective microelectronic package. Thecircuit panel can include no more than two routing layers for routing ofthe address information between a connection site on the circuit panelat which the terminals of the first and second microelectronic packagesare electrically connected and a different connection site at which theterminals of at least a third microelectronic package are electricallyconnected. In one example, the circuit panel may have no more than onerouting layer for the routing of the address information.

In one example, each microelectronic package can include a bufferelement electrically connected to at least some of the terminals and themicroelectronic element in the respective microelectronic package. Eachbuffer element can be configured to regenerate at least one signalreceived at one or more of the terminals of the respectivemicroelectronic package.

In an exemplary embodiment, the circuit panel can include an elementhaving a coefficient of thermal expansion (“CTE”) of less than 12 partsper million per degree Celsius (“ppm/° C.”). The panel contacts exposedat the first and second surfaces can be connected by vias extendingthrough the element. In a particular example, the element can consistessentially of semiconductor, glass, ceramic or liquid crystal polymermaterial.

In accordance with an aspect of the invention, a microelectronicassembly can include a circuit panel having a first surface, a secondsurface opposite the first surface, and panel contacts exposed at eachof the first and second surfaces. First and second microelectronicpackages can have terminals mounted to the panel contacts at the firstand second surfaces, respectively. The circuit panel can electricallyinterconnect at least some terminals of the first microelectronicpackage with at least some corresponding terminals of the secondmicroelectronic package. Each of the first and second microelectronicpackages may include a substrate having first and second opposedsurfaces. A plurality of substrate contacts may be exposed at the firstsurface of the substrate.

Each microelectronic package may include first and secondmicroelectronic elements each having memory storage array function. Thefirst and second microelectronic elements can be spaced apart from oneanother in a direction along the first surface of the substrate and mayhave first parallel edges each extending in the first direction, whereinan axial plane normal to the first surface of the substrate extends inthe first direction and is centered among the first parallel edges. Eachmicroelectronic element may have a front face facing away from the firstsurface of the substrate and a plurality of contacts exposed at thefront face electrically connected with the substrate contacts throughconductive structure.

A plurality of terminals can be exposed at the second surface of thesubstrate at positions within a plurality of parallel columns. Theterminals can be electrically connected with the substrate contacts, theterminals including first terminals exposed at a central region of thesecond surface of the substrate. The first terminals can be configuredto carry address information usable by circuitry within the package todetermine an addressable memory location of a memory storage array ofthe microelectronic elements. The central region may have a width in asecond direction transverse to the first direction, wherein the width ofthe central region is not more than three and one-half times a minimumpitch between any two adjacent columns of the parallel columns of theterminals, and the axial plane intersects the central region.

In a variation of one or more of the above-described examples, the firstterminals may be configured to carry only a majority of the informationneeded to determine an addressable memory location of a memory storagearray of one or more microelectronic elements of the respectivemicroelectronic package.

In another example, the first terminals of a microelectronic package ofthe assembly may be configured to carry at least three-quarters of theaddress information usable by the circuitry within the package todetermine the addressable memory location.

Other structures are also possible. For example, a module can beprovided which includes a circuit panel and a plurality ofmicroelectronic packages mounted to, and electrically connected with thecircuit panel through terminals of each microelectronic package fortransport of signals to and from each microelectronic package. Each ofthe plurality of microelectronic packages of the module may each be inaccordance with one or more of the examples described above.

In accordance with another aspect of the invention, a system can beprovided which includes a microelectronic package and one or more otherelectronic components electrically connected with the microelectronicpackage. Each microelectronic package may be in accordance with one ormore of the examples described above. The system may include a housing,and the microelectronic package and other electronic components may beassembled together with the housing. In a particular example, the systemmay include a second microelectronic package in accordance with one ormore of the examples described above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view illustrating a conventional microelectronicpackage containing a DRAM chip.

FIG. 2 is a diagrammatic schematic diagram illustrating amicroelectronic assembly, e.g., a DIMM module, incorporating a circuitpanel and a plurality of microelectronic packages mounted opposite oneanother to first and second opposite surfaces thereof.

FIG. 3 is a sectional view further illustrating an electricalinterconnection between first and second microelectronic packages and acircuit panel in an assembly such as shown in FIG. 2.

FIG. 4 is a diagrammatic plan view further illustrating the electricalinterconnection between first and second microelectronic packages in anassembly such as shown in FIG. 2.

FIG. 5 is a diagrammatic plan view illustrating an arrangement andsignal assignment of terminals in a microelectronic package according toan embodiment of the invention.

FIG. 6A is a sectional view through line 6A-6A of FIG. 5 furtherillustrating the microelectronic package shown in FIG. 5.

FIG. 6B is a plan view of the microelectronic element of FIG. 6Aillustrating an arrangement of contacts in accordance with theembodiment shown in FIGS. 5 and 6A.

FIG. 6C is a plan view illustrating an alternative arrangement ofcontacts on a microelectronic element according to a variation of theembodiment shown in FIG. 6B.

FIG. 6D is a plan view illustrating another alternative arrangement ofcontacts on a microelectronic element according to a variation of theembodiment shown in FIG. 6B.

FIG. 6E is a sectional view illustrating a microelectronic packageaccording to a variation of the embodiment shown in FIGS. 5 and 6A.

FIG. 7A is a plan view further illustrating an arrangement of terminalsin accordance with the embodiment shown in FIGS. 5 and 6A.

FIG. 7B is a sectional view illustrating a microelectronic assembly andfirst and second microelectronic packages electrically interconnectedtherewith in accordance with an embodiment of the invention.

FIG. 7C is a schematic diagram illustrating a microelectronic assemblyincluding a circuit panel and microelectronic packages electricallyconnected thereto, e.g., a memory module, among others, according to anembodiment of the invention.

FIG. 8 is a plan view illustrating an alternative arrangement ofterminals on a microelectronic package according to a variation of theembodiment shown in FIGS. 5 and 6A.

FIG. 9A is a plan view illustrating an alternative arrangement ofterminals on a microelectronic package according to another variation ofthe embodiment shown in FIGS. 5 and 6A.

FIG. 9B is a sectional view illustrating a microelectronic assembly andfirst and second microelectronic packages as shown in FIG. 9Aelectrically interconnected therewith in accordance with an embodimentof the invention.

FIG. 10A is a sectional view illustrating a microelectronic packageincluding a stacked electrically connected assembly of semiconductorchips therein in accordance with an embodiment of the invention.

FIG. 10B is a sectional view illustrating a microelectronic packageaccording to a variation of the embodiment shown in FIG. 10A.

FIGS. 11A and 11B are a sectional view and a corresponding top viewillustrating a microelectronic package including a stacked electricallyconnected assembly of semiconductor chips therein in accordance with anembodiment of the invention.

FIG. 12 is a sectional view illustrating a microelectronic packageincluding a stacked electrically connected assembly of semiconductorchips therein in accordance with an embodiment of the invention.

FIG. 13A is a sectional view illustrating a microelectronic packageaccording to a variation of the embodiment shown in FIG. 12.

FIG. 13B is a sectional view illustrating a microelectronic packageaccording to another variation of the embodiment shown in FIG. 12.

FIG. 13C is a sectional view illustrating a microelectronic packageaccording to a variation of the embodiment shown in FIG. 13B.

FIG. 14A is a diagrammatic plan view illustrating an arrangement andsignal assignment of terminals in a microelectronic package according toanother embodiment of the invention.

FIG. 14B is a plan view further illustrating an arrangement of terminalsin accordance with the embodiment shown in FIG. 14A.

FIG. 15 is a sectional view through line 15-15 of FIG. 14A furtherillustrating the microelectronic package shown in FIG. 14A.

FIG. 16A is a diagrammatic plan view illustrating an arrangement ofterminals in a microelectronic package according to yet anotherembodiment of the invention.

FIG. 16B is a plan view further illustrating an arrangement and signalassignment of terminals in accordance with the embodiment shown in FIG.16A.

FIG. 17A is a diagrammatic plan view illustrating an arrangement ofterminals in a microelectronic package according to a variation of theembodiment shown in FIGS. 16A and 16B.

FIG. 17B is a plan view further illustrating an arrangement and signalassignment of terminals in accordance with the embodiment shown in FIG.17A.

FIG. 18 is a schematic sectional view illustrating a system according toan embodiment of the invention.

FIG. 19 is a schematic sectional view illustrating a system according toan embodiment of the invention.

DETAILED DESCRIPTION

In view of the illustrative conventional microelectronic package 12described relative to FIG. 1, the inventors have recognized improvementswhich can be made that may help improve the electrical performance of amicroelectronic package incorporating a memory storage array chip, and amicroelectronic assembly that incorporates such microelectronic package.

Improvements can be made particularly for use of a microelectronicpackage when provided in an assembly such as shown in FIGS. 2-4, inwhich a package 12A is mounted to a surface of a circuit panel withanother like package 12B mounted opposite thereto on an opposite surfaceof the circuit panel. The packages 12A, 12B typically are functionallyand mechanically equivalent to one another. Other pairs 12C and 12D; and12E and 12F, of functionally and mechanically equivalent packagestypically are also mounted to the same circuit panel 34. The circuitpanel and the packages assembled thereto may form a portion of anassembly commonly referred to as a dual in-line memory module (“DIMM”).The packages in each oppositely mounted pair of packages, e.g., packages12A, 12B, connect to contacts on opposite surfaces of the circuit panelso that the packages in each pair overlie one another typically by morethan 90% of their respective areas. Local wiring within the circuitpanel 34 connects terminals, e.g., the terminals labeled “1” and “5” oneach package to global wiring on the circuit panel. The global wiringincludes the signal conductors of a bus 36 used to conduct some signalsto connection sites on the circuit panel 34 such as sites I, II and III.For example, the packages 12A, 12B are electrically connected to the bus36 by local wiring coupled to a connection site I, packages 12C, 12D areelectrically connected to the bus by local wiring coupled to connectionsite II, and packages 12E, 12F are electrically connected to the bus bylocal wiring coupled to connection site III.

The circuit panel 34 electrically interconnects the terminals of therespective packages 12A, 12B using local interconnect wiring thatappears similar to a crisscross or “shoelace” pattern in which aterminal labeled “1” near one edge 16 of package 12A connects throughthe circuit panel 34 to a terminal labeled “1” of package 12B near thesame edge 16 of package 12B. However, the edge 16 of package 12B asassembled to circuit panel 34 is far from the edge 16 of package 12A.FIGS. 2-4 further shows that a terminal labeled “5” near an edge 22 ofpackage 12A is connected through the circuit panel 34 to a terminallabeled “5” of package 12B near the same edge 22 of package 12B. Inassembly 38 the edge 22 of package 12A is far from the edge 22 ofpackage 12B.

Connections through the circuit panel between terminals on each package,e.g., package 12A, to the corresponding terminals on the package mountedopposite thereto, i.e., package 12B, are fairly long. As further seen inFIG. 3, in such assembly of like microelectronic packages 12A, 12B, thecircuit panel 34 may electrically interconnect a signal conductor of thebus 36 with the terminal of package 12A marked “1” and the correspondingterminal of package 12B marked “1”, when the same signal from the bus isto be transmitted to each package. Similarly, the circuit panel 34 mayelectrically interconnect another signal conductor of the bus 36 withthe terminal of package 12A marked “2” and the corresponding terminal ofpackage 12B marked “2”. The same connection arrangement may also applyto other signal conductors of the bus and corresponding terminals ofeach package.

Local wiring between the bus 36 on the circuit panel 34 and each packageof the respective pair of packages, e.g., packages 12A, 12B (FIG. 2) ata connection site I of the board can be in form of unterminated stubs.Such local wiring when relatively long may in some cases impact theperformance of the assembly 38 as discussed below. Moreover, the circuitpanel 34 also requires local wiring to electrically interconnect certainterminals of other packages: the pair of packages 12C and 12D, and thepair of packages 12E and 12F to the global wiring of the bus 36, andsuch wiring can also impact the performance of the assembly in the sameway.

FIG. 4 further illustrates the interconnection between microelectronicpackages 12A, 12B of respective pairs of terminals assigned to carrysignals “1”, “2”, “3”, “4”, “5”, “6”, “7”, and “8”. As seen in FIG. 4,because the columns 14, 18 of terminals are near the edges 16, 22,respectively, of each package 12A, 12B, the wiring needed to traversethe circuit panel 34 in a direction 40 transverse to the direction 42 inwhich the columns 14, 18 of terminals extend can be quite long. Inrecognition that the length of a DRAM chip can be in the range of tenmillimeters on each side, the length of the local wiring in a circuitpanel 34 in an assembly 38 seen in FIGS. 2-4 that is required to routethe same signal to the corresponding terminals of two oppositely mountedpackages 12A, 12B can range between five and ten millimeters and maytypically be about seven millimeters.

In some cases, relatively long unterminated wiring on a circuit panelwhich connects the terminals of a package may not severely impact theelectrical performance of the assembly 38. However, when a signal istransferred from a bus 36 of the circuit panel to each of multiple pairsof packages connected to the circuit panel as shown in FIG. 2, theinventors recognize that the electrical lengths of the stubs, i.e., thelocal wiring, that extend from the bus 36 to the terminal connectedthereto on each package potentially impacts the performance of theassembly 38. Signal reflections on the unterminated stubs can travel inthe reverse direction from the connected terminals of each package backonto the bus 36, and thus degrade the signals being transferred from thebus 36 to the packages. The impacts may be tolerable for some packagescontaining microelectronic elements of current manufacture. However, inpresent or future assemblies which operate with increased signalswitching frequencies, low voltage swing signals or both, the inventorsrecognize that the impacts can become severe. For these assemblies,settling time, ringing, jitter, or intersymbol interference of atransmitted signal may increase to an unacceptable degree.

The inventors further recognize that the electrical lengths of theunterminated stubs are usually longer than the local wiring thatconnects the bus 36 on the circuit panel with the terminals of thepackages mounted thereto. Unterminated wiring within each package fromthe package terminals to the semiconductor chip therein adds to thelengths of the stubs.

In a specific example, the bus 36 is a command-address bus of anassembly having a predominant memory storage array function such as aDIMM. The command-address bus 36 can be configured to carry addressinformation transferred to the microelectronic packages that is usableby circuitry within the packages, e.g., row address and column addressdecoders, and bank selection circuitry, if present, to determine anaddressable memory location from among all the available addressablememory locations of a memory storage array within a microelectronicelement in the packages. The command-address bus 36 can be configured tocarry the above-noted address information to connection sites, e.g.,sites I, II, and III shown in FIG. 2. These above-noted addressinformation can then be distributed by local wiring to respective setsof panel contacts on opposite surfaces of the circuit panel, to whichpackages 12A, 12B, 12C, 12D, 12E and 12F are connected.

In a particular example, when the microelectronic element is or includesa DRAM chip, command-address bus 36 can be configured to carry all of agroup of signals of a command-address bus of the microelectronicelement, i.e., command signals, address signals, bank address signalsand clock signals that are transferred to the microelectronic packages,wherein the command signals include write enable, row address strobe,and column address strobe signals, and the clock signals are clocks usedfor sampling the address signals. While the clock signals can be ofvarious types, in one embodiment, the clock signals carried by theseterminals can be one or more pairs of differential clock signalsreceived as differential or true and complement clock signals.

Accordingly, certain embodiments of the invention described hereinprovide a microelectronic package configured so as to permit the lengthsof stubs to be reduced when first and second such packages are mountedopposite one another on opposite surfaces of a circuit panel, e.g., acircuit board, module board or card, or flexible circuit panel.Assemblies which incorporate first and second microelectronic packagesmounted opposite one another on a circuit panel can have significantlyreduced stub lengths between the respective packages. Reducing the stublengths within such assemblies can improve electrical performance, suchas by reducing one or more of settling time, ringing, jitter, orintersymbol interference, among others. Moreover, it may be possible toobtain other benefits as well, such as simplifying the structure of thecircuit panel or reducing the complexity and cost of designing ormanufacturing the circuit panel, or for both designing and manufacturingthe circuit panel.

Thus, a microelectronic package 100 according to an embodiment of theinvention is illustrated in FIGS. 5 through 6B. As seen therein, thepackage can include a substrate 102 on which a plurality of columns104A, 104B are disposed, each column 104A and 104B having at least somefirst terminals 105 disposed within the column. Optionally, a pluralityof columns 106A, 106B are also disposed on the substrate 102, eachcolumn 106A and 106B having second terminals 107 disposed within thecolumn.

As used herein, a statement that an electrically conductive element suchas a terminal, or a contact, is “on” or “disposed on” a supportingelement such as a substrate of a package or a circuit panel does notrequire that the electrically conductive element overlie a surface ofthe supporting element, so long as the electrically conductive elementis available at the surface of the supporting element for contact with atheoretical point moving in a direction perpendicular to the surface ofthe supporting element. Thus, the terminal or contact may project abovethe surface, be recessed relative to the surface, or be flush with thesurface.

The substrate may include a dielectric element, which in some cases canconsist essentially of polymeric material, e.g., a resin or polyimide,among others, and which may be sheet-like. Alternatively, the substrate102 can include a dielectric element having a composite constructionsuch as glass-reinforced epoxy, e.g., of BT resin or FR-4 construction.In another example, the substrate can include a supporting element ofmaterial having a coefficient of thermal expansion (“CTE”) of less than12 parts per million per degree Celsius (“ppm/° C.”), on which theterminals and other conductive structure are disposed. For example, suchlow CTE element can consist essentially of glass, ceramic orsemiconductor material or liquid crystal polymer material, or acombination of such materials.

The terminals 105 and 107 can be disposed at positions within aplurality of columns 104A, 104B, 106A and 106B exposed at a surface 110of the substrate. As used herein, a statement that an electricallyconductive element is “exposed at” a surface of a structure indicatesthat the electrically conductive element is available for contact with atheoretical point moving in a direction perpendicular to the surfacetoward the surface from outside the structure. Thus, a terminal or otherconductive element which is exposed at a surface of a structure canproject from such surface; can be flush with such surface; or can berecessed relative to such surface and exposed through a hole ordepression in the structure. In the example shown in FIG. 5, columns104A and 104B each extend in a first direction along the surface 110 andincludes a plurality of first terminals 105. Columns 106A, 106B may eachinclude a plurality of second terminals 107 and may in some cases beparallel with the columns 104A, 104B and extend in the first directionas well. In a particular example, some second terminals can also bedisposed within columns 104A, 104B. The central region 112 is not widerthan three and one-half times a minimum pitch between adjacent ones ofthe parallel columns of the terminals, as seen and further describedrelative to FIG. 7A below.

In one example, the first terminals can be configured to carry addressinformation usable by circuitry within the package to determine anaddressable memory location from among all the available addressablememory locations of a memory storage array within the microelectronicelement. Thus, in one embodiment, the first terminals are configured tocarry address information transferred to the microelectronic packagewhich is usable by circuitry within the package, e.g., row address andcolumn address decoders, and bank selection circuitry, if present, todetermine an addressable memory location from among all the availableaddressable memory locations of a memory storage array within amicroelectronic element in the package. Typically, the addressinformation carried by the first terminals is sufficient to determinethe addressable memory location. In a particular embodiment, the firstterminals can be configured to carry all the address information used bysuch circuitry within the package to determine an addressable memorylocation within such memory storage array.

In a variation of such embodiment, the first terminals can be configuredto carry a majority of the address information that is used by suchcircuitry within the package to determine an addressable memory locationwithin such memory storage array, and then other terminals such as theabove-referenced second terminals on the package would then beconfigured to carry the remaining part of the address information. Insuch variation, in a particular embodiment, the first terminals areconfigured to carry three quarters or more of the address informationthat is used by such circuitry within the package to determine anaddressable memory location within such memory storage array.

In a particular embodiment, the first terminals may not be configured tocarry chip select information, e.g., information usable to select aparticular chip within the package for access to a memory storagelocation within the chip. In another embodiment, the first terminals mayindeed carry chip select information.

A variety of microelectronic elements, e.g., semiconductor chips, areconfigured to provide memory storage array function. In one example, amicroelectronic element may contain a greater number of active devicesto provide memory storage array function than any other function. In onetype of such microelectronic element, each one of some contacts of aplurality of external contacts at an exterior of the microelectronicelement is dedicated to receiving a respective address signal of aplurality of address signals supplied to the microelectronic element. Inthis case, each of such contacts is able to receive one address signalof the plurality of address signals supplied to the microelectronicelement from an external component, e.g., from a circuit panel viaconnections through a microelectronic package in which themicroelectronic element is incorporated.

In one particular example of this type of microelectronic element, eachof the plurality of address signals present at the external contacts canbe sampled relative to an edge of a clock used by the microelectronicelement, i.e., upon on a transition of the clock between first andsecond different voltage states. That is, each address signal can besampled upon a rising transition between a lower voltage state and ahigher voltage state of the clock, or upon a falling transition betweena higher voltage state and a lower voltage state of the clock. Thus, theplurality of address signals may all be sampled upon the risingtransition of the clock, or may all be sampled upon the fallingtransition of the clock, or in another example, the address signal atone of the external contacts can be sampled upon the rising transitionof the clock and the address signal at one other external contact can besampled upon the falling transition of the clock.

In another type of microelectronic element configured to predominantlyprovide memory storage array function, one or more of the addresscontacts thereon can be used in a multiplexed manner In this example, aparticular external contact of the microelectronic element can beconfigured to receive two or more different signals supplied to themicroelectronic element from the outside. Thus, a first address signalcan be sampled at the particular contact upon a first transition of theclock between the first and second different voltage states (e.g., arising transition), and a signal other than the first address signal canbe sampled at the particular contact upon a second transition of theclock (e.g., a falling transition) between the first and second voltagestates that is opposite the first transition.

In such a multiplexed manner, two different signals can be receivedwithin the same cycle of the clock on the same external contact of themicroelectronic element. In a particular case, multiplexing in thismanner can allow a first address signal and a different signal to bereceived in the same clock cycle on the same external contact of themicroelectronic element. In yet another example, multiplexing in thismanner can allow a first address signal and a second different addresssignal to be received in the same clock cycle on the same externalcontact of the microelectronic element.

In a particular example, the first terminals can be configured to carryall of a group of command signals, address signals, bank address signalsand clock signals which are transferred to the microelectronic package.As mentioned above, the “command signals” are a write enable signal, rowaddress strobe signal, and column address strobe signal utilized by amicroelectronic element within the microelectronic package, when suchmicroelectronic element is a dynamic random access memory storagedevice. “Clock signals” are signals used as clocks for sampling theaddress signals. For example, as seen in FIG. 5, the first terminals caninclude clock signals CK and CKB, row address strobe RAS, column addressstrobe CAS and write enable signals WE, as well as address signals A0through A15 inclusive, and bank address signals BA0, BA1 and BA2.

Although not specifically shown in FIG. 5, other terminals, e.g., secondterminals, can also be disposed in the central region and be configuredto carry other signals, e.g., data signals to and or from themicroelectronic element of the package. Although some first terminals inFIG. 5 are assigned for carrying a power supply voltage (VDD), the powersupply connections as well as connections to ground can be among any ofthe first or second terminals. For ease and clarity of description, theterminals used for connecting to a power supply or to ground are omittedfrom the drawings and need not be mentioned further in the descriptionwhich follows.

Typically, when the microelectronic package has second terminals, thesecond terminals are arranged in one or more columns each having aplurality of second terminals. The second terminals 106A, 106B may bearranged in one or more of first and second peripheral regions 114A,114B of the second surface 110 of the substrate 102, the peripheralregions 114A, 114B being adjacent to first and second opposed edges 116,118 of the second surface 110. The central region 112 can be disposedbetween the first and second peripheral regions 114A, 114B.

As seen in the sectional view of FIG. 6A, a microelectronic element 130within microelectronic package 100 has a rear face 131 facing the secondsurface 110 of the substrate 102, and a front face 134 opposite the rearface 131, and first and second opposed edges 170, 172 extending betweenthe front and rear faces. The microelectronic element, e.g., asemiconductor chip, or stacked arrangement of semiconductor chips, canbe configured to provide memory storage array function, and in oneexample, may be configured to predominantly provide memory storage arrayfunction. In such microelectronic element, the number of active devices,e.g., transistors, therein which are configured, i.e., constructed andinterconnected with other devices, to provide memory storage arrayfunction may be greater than the number of active devices which areconfigured to provide any other function.

Thus, in one example, a microelectronic element such as a DRAM chip mayhave memory storage array function as its primary or sole function.Alternatively, in another example, such microelectronic element may havemixed use and may incorporate active devices configured to providememory storage array function, and also incorporate other active devicesconfigured to provide another function such as processor function, orsignal processor or graphics processor function, among others. In thiscase, the microelectronic element may in some cases still have a greaternumber of active devices configured to provide the memory storage arrayfunction than any other function of the microelectronic element.

An axial plane 174 normal to the face 134 of the microelectronic element130 intersects the second surface 110 of the substrate 102 along a linewhich extends in the first direction and is parallel to and centeredwith respect to the first and second edges 170, 172 of themicroelectronic element 130. As further seen in FIG. 6A and in acorresponding plan view of FIG. 6B, an edge 170 of microelectronicelement 130 extends in the first direction 142 and a column 138 ofcontacts 132 exposed at the front face 134 of the microelectronicelement and adjacent to edge 170 can extend in the same first direction142 along the front face 134. Another edge 172 of microelectronicelement 130, parallel to edge 170, extends in the first direction 142and a second column 139 of contacts 132 exposed at the front face 134 ofthe microelectronic element may extend in the same first direction 142along the front face 134 adjacent to edge 172. As further shown in FIG.6B, a column of contacts on the microelectronic element can be fullypopulated as in the case of column 138, or a column of contacts may haveonly have contacts at some of the positions within the column, as in thecase of column 139. Conductive structure such as wire bonds 173 (FIG.6A) may electrically connect the contacts 132 with correspondingcontacts 136 on a first surface 108 of the substrate.

Referring to FIG. 6A, the axial plane 174 of microelectronic element130, extending in the first direction parallel to edges 170, 172,intersects the central region 112 of the second surface 110 of thesubstrate, the central region 112 of the substrate surface being whereat least a first column 104A and a second column 104B of terminals, eachhaving at least some first terminals 105 are disposed within the columnof the microelectronic package. Second terminals, if present, may bedisposed in one or more of the peripheral regions 114A, 114B of thesubstrate surface 110. Alternatively or in addition thereto, one or moresecond terminals may be disposed in the central region, such as can bedisposed within columns 104A, 104B. As further seen in FIG. 6A, joiningelements 154 attached to terminals can include a bond metal, e.g.,solder, tin, indium or eutectic, or other electrically conductive bondmaterial attached to the terminals that can be used to join theterminals of the package 100 to a component external to the package,such as to corresponding contacts of a circuit panel.

FIG. 6C illustrates a variation of the embodiment shown in FIG. 6B inwhich the contacts 132 of a microelectronic element 180 exposed at thefront face thereof are disposed in columns or rows adjacent to andaligned with respective peripheral edges 170, 172, 176, 178 of themicroelectronic element 180. Edges 170, 172 are parallel and extend in afirst direction 142. FIG. 6C illustrates the location of an axial plane174 of the microelectronic element 180. In such variation, the axialplane 174 is shown to extend in the first direction and is centeredamong the parallel edges 170, 172.

FIG. 6D illustrates another variation of the embodiment shown in FIG. 6Bin which the contacts of a microelectronic element 190 are disposed incolumns 188 and 189 adjacent to edges 170, 172 of the microelectronicelement. However, in this case, the microelectronic element 190 includesa semiconductor chip having a conductive redistribution layer thereon,and the contacts 132 can include redistribution contacts which areconnected to the contacts 192, 194 of the semiconductor chip byconductive traces, or metalized vias formed in contact with the contacts192, 194 of the semiconductor chip (or which can be connected to thecontacts 192 194 of the chip by both metalized vias and traces). In thisexample, the axial plane 174 intersects the face 196 of themicroelectronic element along a line centered among the columns of 188,189 of redistribution contacts.

In the package 100 as shown in FIG. 6A, the wire bonds 173 electricallyconnecting the microelectronic element 130 with the substrate 102 may beformed starting from the microelectronic element 130, in which case thewire bond forms a ball 175 on the contact 132 of the microelectronicelement and is wedge-bonded to the corresponding substrate contact 136.FIG. 6E shows a package 101 according to a variation thereof in whichthe wire bond 183 forms a ball 185 on the contact 136 of the substrateand is wedge-bonded to the corresponding contact 132 of themicroelectronic element 130. The variation of FIG. 6E may be employed ifdesired to reduce a height 103 of the microelectronic package 101, asthe wire bonds 183 formed in this way can generally have lower heightexcursion above the contacts 132 than the wire bonds 173 shown in FIG.6A.

FIG. 7A is a plan view of the package 100 looking toward aterminal-bearing surface 110 of the substrate therein. Columns 104A,104B in which first terminals are disposed can lie within a centralregion 112 of the surface 110, and columns 106A, 106B in which secondterminals are disposed can lie within one or more peripheral regions114A, 114B of the surface 110. The smallest distance between any twoadjacent columns of terminals on the substrate is the minimum pitch 150as shown in FIG. 7A. The minimum pitch is in a direction 164perpendicular to the direction 162 in which the terminals in aparticular column, e.g., column 104A are arranged. In the example shownin FIG. 7A, the minimum pitch 150 occurs between columns 104A, 104Bwhich are closest to one another. With continued reference to FIG. 7A,the central region 112 has a width 152 along the substrate surface 110in the direction 164 of the pitch. In a particular example, the width152 may be not greater than three and one-half times the minimum pitch150 between any two adjacent columns of the terminals, i.e., not morethan three and one-half times the minimum pitch 150 between the closestadjacent columns 104A, 104B.

FIG. 7B illustrates a microelectronic assembly 300 of a circuit panel354 and first and second microelectronic packages 100A, 100B, each beinga microelectronic package 100 having a structure according to one ormore of the embodiments described above relative to FIGS. 5-6E.Referring to FIG. 7A, each package 100A, 100B may have the same signalsassigned to the respective locations of terminals on the package, andthe columns 104A, 104B, 106A, 106B of terminals on each package can bearranged at the same locations in x and y orthogonal directions 164, 162relative to an edge 116 of the substrate. The packages 100A, 100B areelectrically connected to contacts 360, 362, respectively, exposed atfirst and second opposite surfaces 350, 352 of the circuit panel 354,respectively.

The circuit panel can be of various types, such as a printed circuitboard used in a dual inline memory module (“DIMM”) module, a circuitboard or panel to be connected with other components in a system, or amotherboard, among others. In a particular embodiment, the circuit panelmay include an element having a coefficient of thermal expansion (“CTE”)of less than 12 parts per million per degree Celsius (“ppm/° C.”),wherein the panel contacts at the first and second surfaces areconnected by vias extending through the element. For example, theelement may consist essentially of semiconductor, glass, ceramic orliquid crystal polymer material.

In the example shown in FIG. 7B, the first terminals 105 in the columns104A, 104B can be disposed at positions within a grid 104 on the firstpackage 100A, and the first terminals 105 in the columns 104A, 104B onthe second package 100B can be disposed at positions of within a similargrid 104. Each grid of terminals may be fully populated, i.e., having aterminal at each position of each grid. Alternatively, there may not bea terminal disposed at one or more positions of the grid on a package.As apparent from FIG. 7B, the grids 104 which include first terminals oneach package 100A, 100B can be aligned within a distance of one ballpitch of one another in x and y orthogonal directions parallel to thesurface 350 of the circuit panel, the ball pitch being no greater than aminimum pitch between any two adjacent parallel columns of the terminalson either package. In a particular example, the grids 104 may becoincident with one another. As used herein, when grids of terminals ofpackages at opposite surfaces of a circuit panel are “coincident” withone another, the alignment can be within customary manufacturingtolerances or can be within a tolerance of less than one-half of oneball pitch of one another in x and y orthogonal directions parallel tothe first and second circuit panel surfaces, the ball pitch being asdescribed above.

Wiring within the circuit panel 354 electrically connects the terminalsin column 104A of package 100A with terminals in column 104A of package100B, as shown. The wiring that forms the electrical connections isshown schematically by the dashed line 320 in FIG. 7B, since the wiringcan be hidden from view in the example shown in FIG. 7B. Similarly,wiring within the circuit panel 354 electrically connects the terminalsin column 104B of package 100A with terminals in column 104B of package100B, and the electrical interconnections between such terminals isshown schematically by the dashed line 322 in FIG. 7B.

Further, in a particular example as shown in FIG. 7B, since there aretwo columns 104A, 104B of first terminals in each grid, and the gridsare aligned within at least one ball pitch of one another, then thewiring on the circuit panel 354 required to connect one of the firstterminals labeled “A” of package 100A with a corresponding one of thefirst terminals labeled “A” of package 100B can be relatively short.Specifically, when each grid 104 on each package has two columns 104A,104B, and the grids 104 are aligned in the above-described manner, thena terminal of the first column 104A of the first package 100A is alignedwithin one ball pitch of a terminal of the second column 104B of thesecond package 100B in x and y orthogonal directions parallel to thefirst surface 350 of the circuit panel, the first surface 350 being amajor surface of the circuit panel. In addition, a terminal of thesecond column 104B of the first package 100A is aligned within one ballpitch of a terminal of the first column 104A of the second package in xand y orthogonal directions parallel to the first surface 350 of thecircuit panel.

Therefore, the electrical lengths of stubs on the circuit panel 354 thatelectrically connect a first terminal of the first column of package100A with the corresponding first terminal of the first column of thesecond package 100B can be less than seven times a minimum pitch of thefirst terminals on each package: for example, less than seven times thepitch 150 between columns 104A, 104B of first terminals in FIG. 7A.Stated another way, the total combined length of the conductive elementsconnecting a pair of electrically coupled first and second panelcontacts 360, 362 exposed at the first and second surfaces of thecircuit panel to the corresponding conductor of the bus 36 on thecircuit panel can be less than seven times a smallest pitch of the panelcontacts.

In another example, the total combined length of the conductive elementsconnecting a pair of electrically coupled first and second panelcontacts 360, 362 may be approximately the same as a thickness 356 ofthe circuit panel 354 between first and second surfaces 350, 352. In yetanother example, the electrical length of the connection between a firstterminal in column 104A of the first package 100A with the correspondingfirst terminal in column 104A on the second package 100B may beapproximately the same as the thickness 356 of the circuit panel 354.

The reductions in the lengths of these electrical connections can reducestub lengths from bus 36 (FIG. 2) on the circuit panel to the connectionsites of the packages thereon. The reduced stub lengths can improveelectrical performance, such as by reducing one or more of settlingtime, ringing, jitter, or intersymbol interference, among others, forthe above-noted signals of the bus 36.

Moreover, it may be possible to obtain other benefits as well, such assimplifying the structure of the circuit panel 354 or reducing thecomplexity and cost of designing or manufacturing the circuit panel.That is, connections on the circuit panel may require fewer layers ofwiring to interconnect first terminals of each package to routing layerswithin the circuit panel which constitute a set of conductors whichcarry the address information or carry the address information and otherinformation as described above.

In addition, the number of global routing layers of wiring on thecircuit panel needed to implement a bus 36 such as used to transmit theabove-noted address information or command and address information asdescribed above can also be reduced when the microelectronic packagesattached thereto are constructed according to the principles herein.Specifically, the number of required routing layers may in some cases bereduced to two or fewer routing layers. In a particular example, theremay be no more than one routing layer for routing of the above-notedaddress information, or for routing of all above-noted command signals,address signals, bank address signals, and clock signals of acommand-address bus 36. However, on the circuit panel, there may be agreater number of routing layers which carry information other than theabove-noted address information or carry signals other than thecommand-address bus signals.

In a particular example in which the first terminals of eachmicroelectronic package are disposed at positions within a single columnof the grid 104 of the respective microelectronic package, the circuitpanel 354 may include no more than one routing layer for global routingof all of the address information between a connection site on thecircuit panel at which the terminals of the first and secondmicroelectronic packages 100A, 100B are electrically connected and adifferent connection site at which the terminals of at least a thirdmicroelectronic package are electrically connected.

In one embodiment in which the first terminals of each microelectronicpackage are disposed at positions within no more than two parallelcolumns of the grid 104 of the respective microelectronic package, thecircuit panel 354 may include no more than two routing layers for globalrouting of all of the address information between a connection site onthe circuit panel at which the terminals of the first and secondmicroelectronic packages 100A, 100B are electrically connected and adifferent connection site at which the terminals of at least a thirdmicroelectronic package are electrically connected. In a particularexample, in such an embodiment, there may be no more than one routinglayer for the above-noted global routing.

FIG. 7C illustrates a microelectronic assembly such as, for example, aDIMM, among others, incorporating a circuit panel and a plurality ofmicroelectronic packages mounted opposite one another to first andsecond opposite surfaces thereof. As seen in FIG. 7C, the above-notedaddress signals or command-address bus signals can be routed on a bus36, e.g., an address bus or command-address bus on the circuit panel orcircuit board 354 in at least one direction 143 between connection sitesI, II or III at which respective pairs of microelectronic packages 100A,110B are connected to opposite sides of the circuit panel. Signals ofsuch bus 36 reach each pair of packages at the respective connectionsites I, II or III at slightly different times.

The at least one direction 143 can be transverse or orthogonal to adirection 142 in which at least one column 138 of a plurality ofcontacts on at least one microelectronic element within each package100A or 100B extends. In such way, the signal conductors of the bus 36on (i.e., on or within) the circuit panel 354 can in some cases bespaced apart from one another in a direction 142 which is parallel tothe at least one column 138 of contacts on a microelectronic elementwithin a package 100A, or 100B connected to the circuit panel.

Such configuration, particularly when the first terminals 105 of eachmicroelectronic package are arranged in one or more columns 104A, 104Bextending in such direction 142, may help simplify the routing of signalconductors of one or more global routing layers on the circuit panelused to route the signals of the bus 36. For example, it may be possibleto simplify routing of the command-address bus signals on a circuitpanel when relatively few first terminals are disposed at the samevertical layout position on each package. Thus, in the example shown inFIG. 5, only two first terminals are disposed at the same verticallayout position on each package, such as the first terminals configuredto receive address signals A3 and A1.

In an exemplary embodiment, the microelectronic assembly 354 can have amicroelectronic element 358 that can include a semiconductor chipconfigured to perform buffering of at least some signals transferred tothe microelectronic packages 100A, 100B of the assembly 354. Themicroelectronic element 358 can be configured predominantly to perform alogic function, such as a solid state drive controller, and one or moreof the microelectronic elements 358 in the microelectronic packages 100Aand 100B can each include memory storage elements such as nonvolatileflash memory.

The microelectronic element 358 can include a special purpose processorthat is configured to relieve a central processing unit of a system suchas the system 1500 (FIG. 18) from supervision of transfers of data toand from the memory storage elements included in the microelectronicelements 358. Such a microelectronic element 358 including a solid statedrive controller can provide direct memory access to and from a data buson a motherboard (e.g., the circuit panel 1502 shown in FIG. 18) of asystem such as the system 1300. In a particular embodiment, themicroelectronic element 358 can have a buffering function. Such amicroelectronic element 358 can be configured to help provide impedanceisolation for each of the microelectronic elements 358 with respect tocomponents external to the microelectronic assembly 354.

In a particular embodiment, the first terminals 104 of themicroelectronic package can be configured to carry information thatcontrols an operating mode of the microelectronic element 101. Morespecifically, the first terminals can be configured to carry all of aparticular set of command signals and/or clock signals transferred tothe microelectronic package 100. In one embodiment, the first terminals104 can be configured to carry all of the command signals, addresssignals, bank address signals, and clock signals transferred to themicroelectronic package 100 from an external component, wherein thecommand signals include row address strobe, column address strobe andwrite enable. In such embodiment, the first chip can be configured toregenerate the information that controls the operating mode.Alternatively, or in addition thereto, the first chip can be configuredto partially or fully decode the information that controls the operatingmode of the microelectronic element. In such embodiment, each secondchip may or may not be configured to fully decode one or more of addressinformation, command information, or information that controls anoperating mode of the microelectronic element.

Microelectronic packages having other arrangements of terminals thereoncan be provided. For example, in the microelectronic package 400illustrated in FIG. 8, four columns 404A, 404B, 404C, and 404D ofterminals are disposed in a central region 112 of the substrate surface,these columns containing the first terminals that are configured tocarry the above-noted address information, or in a particularembodiment, are configured to carry all of the above-noted commandsignals, address signals, bank address signals and clock signals used tosample the address signals. In a particular example thereof, secondterminals can also be disposed within the columns 404A, 404B, 404C,404D, which are configured to carry information other than theabove-noted information or signals carried by the first terminals. Inanother example (not shown), it is also possible for the first terminalsof a microelectronic package to be disposed at positions within threecolumns of terminals.

In the microelectronic package 500 illustrated in FIGS. 9A and 9B, thefirst terminals are arranged at positions within a single column 504disposed in the central region 512 of the substrate surface, the singlecolumn extending in a direction parallel to the edges 516, 518 of themicroelectronic package. Hereinafter, unless otherwise noted, for easeand clarity of description, the second terminals may be omitted from thefigures illustrating various aspects of the invention, although thesecond terminals may nevertheless be present in such embodiments.

In the particular example seen in FIG. 9A, the minimum pitch between anytwo columns of terminals on the substrate is the pitch 552 between theadjacent columns 506B and 506C of second terminals disposed inperipheral region 514B of the substrate surface. The width 554 of thecentral region is not greater than three and one-half times the minimumpitch 552 between the columns 506B and 506C of terminals.

FIG. 10A illustrates a microelectronic package 600 according to aparticular example in which the microelectronic element includes avertical stack 630 of an electrically interconnected first semiconductorchip 632 and a plurality of second semiconductor chips 634, each havinga contact-bearing front face 631 that faces away from the substrate 602and a rear face that faces toward the first surface of the substrate.Wire bonds 635 electrically interconnect the contacts 626 on thesemiconductor chips 632, 634 with corresponding contacts 636 on thesubstrate. Spacers 638 can be disposed between adjacent faces of thesemiconductor chips 634, and a spacer 638 can be disposed between thecontact-bearing face 631 of the semiconductor chip 632 and a rear faceof semiconductor chip 634. In some cases, adhesive layers (not shown)can be provided between each spacer and the faces of the semiconductorchips adjacent to such spacer. As shown in FIG. 10A, the one or moresecond semiconductor chips 634 are electrically interconnected with thefirst semiconductor chip 632. For example, as seen in FIG. 10A, thereare three vertically stacked second semiconductor chips 634 in which thefaces 631 thereof are parallel to one another.

In the microelectronic package 600 seen in FIG. 10A, each of the firstand second semiconductor chips 632, 634 can be configured such that eachsuch semiconductor chip has memory storage array function. In oneexample, each such semiconductor chip can embody a greater number ofactive devices to provide memory storage array function than any otherfunction. For example, each of the first and second semiconductor chipsmay include a memory storage array and all circuitry required forinputting data to and outputting data from the memory storage array. Forexample, when the memory storage array in each semiconductor chip iswriteable, each of the semiconductor chips may include circuitryconfigured to receive external data input from terminals of the package,as well as circuitry configured to transfer data output from suchsemiconductor chip to terminals of the package. Thus, each first andeach second semiconductor chip 632, 634 can be a dynamic random accessmemory (“DRAM”) chip or other memory chip which is capable of inputtingand outputting data from the memory storage array within suchsemiconductor chip and receiving and transmitting such data to acomponent external to the microelectronic package. Stated another way,in such case, signals to and from the memory storage array within eachDRAM chip or other memory chip does not require buffering by anadditional semiconductor chip within the microelectronic package.

Alternatively, in another example, the one or more second semiconductorchips 634 may embody a greater number of active devices to providememory storage array function than any other function, but the firstsemiconductor chip 632 may be a different type of chip. In this case,the first semiconductor chip 632 can be configured, e.g., designed,constructed, or set up, to buffer signals, i.e., regenerate signalsreceived at the terminals for transfer to the one or more secondsemiconductor chips 634, or to regenerate signals received from one ormore of the second semiconductor chips 634 for transfer to theterminals, or to regenerate signals being transferred in both directionsfrom the terminals to the one or more second semiconductor chips 634;and from the one or more semiconductor chips to the terminals of themicroelectronic package. Alternatively or in addition to regeneratingsignals as described above, in a particular example, the firstsemiconductor chip can be configured to partially or fully decode atleast one of address information or command information received at theterminals, such as at the first terminals. The first chip can thenoutput the result of such partial or full decoding for transfer to theone or more second semiconductor chips 634.

In a particular example, the first semiconductor chip can be configuredto buffer the command signals, address signals and clock signals whichare transferred to the one or more second semiconductor chips. Forexample, the first semiconductor chip 632 can be a buffer chip whichembodies a greater number of active devices to provide a bufferingfunction in transferring signals to other devices, e.g., to the one ormore second semiconductor chips 634, than for any other function. Then,the one or more second semiconductor chips may be reduced function chipswhich have memory storage arrays but which can omit circuitry common toDRAM chips, such as buffer circuitry, decoders or predecoders orwordline drivers, among others. In that case, the first chip 632 mayfunction as a “master” chip in the stack and to control operations ineach of the second semiconductor chips 634.

In a particular example, the second semiconductor chips may beconfigured such that they are not capable of performing the bufferingfunction, and so the stacked arrangement of the first and secondsemiconductor chips is configured such that the buffering functionrequired in the microelectronic package can be performed by the firstsemiconductor chip, and cannot be performed by any of the secondsemiconductor chips in the stacked arrangement.

In any of the embodiments described herein, the one or more secondsemiconductor chips can be implemented in one or more of the followingtechnologies: DRAM, NAND flash memory, RRAM (“resistive RAM” or“resistive random access memory”), phase-change memory (“PCM”),magnetoresistive random access memory, e.g. such as may embodimenttunnel junction devices, static random access memory (“SRAM”),spin-torque RAM, or content-addressable memory, among others.

FIG. 10B illustrates a variation of the above-described embodiment inwhich the first semiconductor chip 633 within microelectronic package601 is configured to buffer at least some signals received at terminalsof the package, e.g., the first terminals, for transmission to othersemiconductor chips 634 within the package. In this variation, the firstsemiconductor chip 633 can be mounted to the substrate 602 in flip-chiporientation, i.e., having contacts 643 on a face thereof facingcorresponding contacts on the substrate 602 and being joined theretosuch as by solder, other bond metal or other conductive material.

FIG. 11A is a sectional view and FIG. 11B is a corresponding plan viewillustrating a microelectronic package 660 according to a furthervariation in which the second semiconductor chips 634 are mounted instair-step manner relative to one another such that the contacts of thefirst semiconductor chip 632 are exposed beyond an edge 618 of thesecond semiconductor chip 634A immediately above the first semiconductorchip 632, and the contacts of that semiconductor chip 634A are exposedbeyond an edge 618 of the second semiconductor chip 634B immediatelyabove that second semiconductor chip. Electrical connections between thefirst and second chips and the substrate and among the chips can beprovided by wire bonds 635 which electrically connect adjacent chipswithin the stack of semiconductor chips, or wire bonds 637 whichelectrically connect the chips directly to the package substrate 662.

FIG. 12 illustrates a microelectronic package 670 according to a furthervariation of the embodiment described above relative to FIG. 10A, inwhich connections between contacts of the one or more secondsemiconductor chips 634 can include traces or leads 640 which extendalong one or more edges of a unit of stacked semiconductor chips 630,i.e., along edges of the semiconductor chips 634 within such unit 630.Unit 630 is mounted and electrically interconnected with contacts 627 ofthe first semiconductor chip 632, such as with a bond metal, e.g.,solder, tin, gold, indium, a eutectic, or electrically conductive bumps,or both, which may in some cases include conductive posts, e.g.,micropillars. Traces 654 may extend along a face 631 of the firstsemiconductor chip from the contacts 627 to second contacts 626, whichin turn can be electrically connected with the substrate, such asthrough wire bonds 645.

The electrical connections between the second semiconductor chips 634may further include traces 644 which extend along front faces of thesecond semiconductor chips 634. As further shown in FIG. 12, the frontfaces 642 of the second semiconductor chips may face upwardly away fromthe substrate 602 or downwardly towards the substrate 602.

FIG. 13A further illustrates a microelectronic package 680 in which asecond semiconductor chip 634 has contacts 647 facing contacts 627 ofthe first chip and joined thereto in flip-chip manner, such as through abond metal, e.g., solder, tin, gold, indium, a eutectic, or electricallyconductive bumps, or both. Traces 654 may electrically connect thecontacts 627 with other contacts 626 on the first chip that areelectrically connected to the substrate, such as through wire bonds.

FIG. 13B further illustrates a microelectronic package 690 according toa particular example in which the one or more second semiconductor chips634 are electrically connected with one another by through-silicon vias(“TSVs”) 650 that extend in a direction of the thicknesses 652 of atleast some of the second semiconductor chips 634, i.e., in a directionnormal to the faces 642 of the chips 634. As seen in FIG. 13B, in oneexample, the TSVs 650 can be electrically connected with contacts 627 ofthe first semiconductor chip 632, such as through a bond metal, e.g.,solder, tin, gold, indium, a eutectic, or electrically conductive bumps,or both, which may in some cases include conductive posts, e.g.,micropillars. Traces 654 may extend along a face 631 of the firstsemiconductor chip from the contacts 627 to second contacts 626, whichin turn can be wire-bonded to the substrate.

In one example, information or signals received at terminals of thepackage 690, such as at the first terminals, the second terminals, orboth, can be received by the first semiconductor chip 632 through wirebonds 645 that are joined to substrate contacts 636, which in turn arejoined to such terminals of the microelectronic package. The firstsemiconductor chip 632, operating as a buffer element, can thenregenerate the received information or signals and then transfer theregenerated information or signals to the one or more secondsemiconductor chips, e.g., through the connections between the first andsecond chips 632, 634 and through the TSVs 650 within the stack ofsecond chips 634.

FIG. 13C illustrates a variation of the microelectronic package shown inFIG. 13B. Unlike the package shown in FIG. 13B, semiconductor chip 664,which is configured to regenerate or at least partially decode addressinformation or other information, e.g., regenerate signals for transferto other semiconductor chips in the package, is not located adjacent tothe first surface 108 of the substrate 602. Rather, in this case, thesemiconductor chip 664 can be disposed at a position within the packagethat overlies one or more other semiconductor chips. For example, asshown in FIG. 13C, the chip 664 at least partially overlies thesemiconductor chip 662 that is disposed adjacent to the first surface108 of the substrate 602 and at least partially overlies semiconductorchips 663A, 663B and 663C which are disposed atop semiconductor chip662.

In one example, the semiconductor chips 662 and 663A, 663B and 663C mayinclude memory storage arrays. As in the examples described above, suchchips 662, and 663A, 663B and 663C may each incorporate circuitsconfigured to buffer, e.g., temporarily store, data that is to bewritten to such chip, or data that is being read from such chip, orboth. Alternatively, the chips 662, and 663A, 663B and 663C may be morelimited in function and may need to be used together with at least oneother chip that is configured to temporarily store data that is to bewritten to such chip or data that is being read from such chip, or both.

The semiconductor chip 664 can be electrically connected to terminals ofthe microelectronic package, e.g., to grids in which the first terminals604 and the second terminals 606 are disposed, through electricallyconductive structure, e.g., wire bonds 665, that partially overlies afront face 631 of the semiconductor chip 663A and that connects tocontacts 636 exposed at the first surface 108 of the substrate 602. Theelectrically conductive structure, e.g., the wire bonds 665, canelectrically connect to the semiconductor chip 664 through contacts 638on a chip 663A and through conductors (not shown) that extend along theface 631 of the chip 663A, or along a confronting face 641 of the chip664, or along the faces 631, 641 of both of the chips 663A, 664. Asindicated above, the semiconductor chip 664 may be configured toregenerate or at least partially decode signals or information that itreceives through the conductive structure, e.g., the wire bonds 665, andit may be configured to transfer the regenerated or at least partiallydecoded signals or information to other chips within the package such asto the chips 662, and 663A, 663B and 663C.

As further seen in FIG. 13C, the semiconductor chips 662, 663A, 663B and663C can be electrically connected to the semiconductor chip 664 and toone another by a plurality of through-silicon vias (“TSVs”) 672, 674,and 676 that can extend through one, two, or three or more of suchchips. Each such TSV may electrically connect with wiring within thepackage, e.g., conductive pads or traces of two or more of thesemiconductor chips 662, 663A, 663B and 663C and 664. In a particularexample (not shown), through silicon vias may extend through thethicknesses of all semiconductor chips 662, 663A, 663B and 663C, eventhough each through silicon via may not electrically connect with eachsuch semiconductor chip through which it extends.

As further seen in FIG. 13C, a heat sink or heat spreader 668, which mayinclude a plurality of fins 671, can be thermally coupled to a face ofthe semiconductor chip 664, e.g., a rear face 633 thereof, such asthrough a thermally conductive material such as thermal adhesive,thermally conductive grease, or solder, among others.

The microelectronic assembly 695 shown in FIG. 13C may be configured tooperate as a memory module capable of transferring a designated numberof data bits per cycle onto or off of the microelectronic packagethrough the first and second terminals provided therefor on thesubstrate. For example, the microelectronic assembly may be configuredto transfer a number of data bits such as thirty-two data bits,sixty-four data bits, or ninety-six data bits, among other possibleconfigurations, to or from an external component such as a circuit panelthat can be electrically connected with the terminals 604, 606. Inanother example, when the bits transferred to and from the packageinclude error correction code bits, the number of bits transferred percycle to or from the package may be thirty-six bits, seventy-two bits,or one-hundred-eight bits. Other data widths are possible other thanthose that are specifically described here.

FIGS. 14A, 14B, and 15 illustrate a microelectronic package 1100according to a further variation of one or more of the above-describedembodiments. As seen in FIGS. 14A, 14B, and 15, the package 1100includes first and second microelectronic elements 1130, 1131 that arespaced apart from one another on a first surface 1108 of the substrate1102. Each microelectronic element 1130, 1131 has first parallel edges1170 extending away from a face 1142 of the respective microelectronicelement which faces away from the substrate 1102, and second paralleledges 1172 that extend in a direction transverse or orthogonal to adirection in which the first edges extend.

The contacts 1138 of the microelectronic elements are electricallyconnected with corresponding substrate contacts 1148 on the firstsurface 1108 of the substrate 1102. In turn, some of the substratecontacts 1148 are electrically connected with first terminals 1104disposed in a central region 1112 on the second surface 1110, such asthrough electrically conductive traces 1144, or through electricallyconductive vias 1146, or through both traces and vias. In someembodiments, some of the substrate contacts 1148 may instead beelectrically connected with second terminals 1162 in one or moreperipheral regions 1164 of the second surface. FIG. 14A illustratespossible signal assignments of the terminals 1104, 1162 on the package.

As in the above-described embodiments, the central region 1112 of thesubstrate surface 1110 has a width 1154 that is not greater than threeand one-half times a minimum pitch 1152 between any two adjacent columnsof terminals on the package, where each of the two adjacent columns hasa plurality of terminals therein. An axial plane 1150 normal to thesurface 1110 of the substrate 1102 intersects the surface 1110 along aline which is parallel to and centered among the first edges 1170 of thefirst and second microelectronic elements 1130, 1131. In one example, anaxis 1151 along which a column of first terminals 1104 extends can bedisposed between adjacent edges 1134, 1135 of the first and secondmicroelectronic elements as shown therein. This can be true for the axesof more than one columns of the terminals.

Alternatively, although not shown in FIGS. 14A-B and 15, the axis alongwhich a column of the first terminals 1104 extends can overlie one ormore of the faces 1140 of the first and second microelectronic elements1130, 1131, and this may be true for the axes of more than one column.There may be four columns of terminals or fewer in the central region1112 of the surface 1110. As in the above-described embodiments, thereneed not be more than a single column of first terminals 1104 in thecentral region. As further shown in FIG. 15, the faces 1142 of the firstand second microelectronic elements can extend within a single plane1124 parallel to the first surface 1108 of the substrate 1102.

FIGS. 16A-16B illustrate a microelectronic package 1200 according to avariation of the embodiment seen in FIGS. 14A-B and 15 which, inaddition to first and second microelectronic elements 1230, 1231 havingthe same arrangement and electrical interconnections within the package1200 as discussed above regarding microelectronic package 1100 (FIGS.14A-B, 15), further includes third and fourth microelectronic elements1233 and 1235. Like the first and second microelectronic elements, eachof the third and fourth microelectronic elements may embody a greaternumber of active devices to provide memory storage array function thanany other function. Like the first and second microelectronic elements,the third and fourth microelectronic elements 1233 and 1235 are mountedface-up on the substrate 1202 and are electrically interconnected withthe first terminals 1204 of the package, such as through electricalconnections extending above the respective contact-bearing faces (notshown) of the microelectronic elements. The electrical connections canbe wire bonds, as discussed above.

The terminals 1204 of the microelectronic package can be arranged withina central region 1212 having width 1252 no greater than three andone-half times the minimum pitch between columns of terminals, asdescribed above. As further shown in FIG. 16A, the intersection of theaxial plane 1250 with the substrate 1202 can be centered among all ofthe first parallel edges 1270 of the first, second, third and fourthmicroelectronic elements within the package 1200.

In like manner to that described above relative to FIGS. 14A-B and 15,the contact-bearing faces (not shown) of the microelectronic elements1230, 1231, 1233 and 1235 can be arranged within the package 1200 suchthat all of such faces are co-planar, i.e., extend within a singleplane, i.e., such as a single plane 1124 as illustrated in FIG. 15.

FIG. 16B illustrates a possible signal assignment of terminals on thepackage 1200 in which first terminals 1204 are arranged in one or morecolumns in the central region and second terminals 1206 are arranged inmultiple areas near peripheral edges 1260, 1261, 1262 and 1263 of thepackage. In this case, some of the second terminals 1206 can be disposedat positions within a grid such as grid 1270, and some second terminalscan be disposed at positions within a grid such as grid 1272. Inaddition, some second terminals can be disposed at positions within agrid such as grid 1274, and some second terminals can be disposed atpositions within a grid 1276.

As shown in FIG. 16B, the signal class assignments of the secondterminals 1206 in the grid 1276 can be symmetric about a vertical axis1251 that can extend within the axial plane 1250, and the signal classassignments of the second terminals in the grid 1274 can be symmetricabout the vertical axis 1251. As used herein, two signal classassignments can be symmetric with respect to one another if the signalassignments are in the same class of assignments, even if the numericalindex within the class differs. Exemplary signal class assignments caninclude data signals, data strobe signals, data strobe complementsignals, and data mask signals. In a particular example, in the grid1276, the second terminals 1206 having signal assignments DQSH# andDQSL# are symmetric about the vertical axis 1251 with respect to theirsignal class assignment, which is data strobe complement, even thoughthose second terminals have different signal assignments.

As further shown in FIG. 16B, the assignments of the data signals to thespatial positions of the second terminals on the microelectronicpackage, such as for data signals DQ0, DQ1, . . . , for example, canhave modulo-X symmetry about the vertical axis 1251. The modulo-Xsymmetry can help preserve signal integrity in an assembly 300 such asseen in FIG. 7B, in which one or more pairs of first and second packagesare mounted opposite one another to a circuit panel, and the circuitpanel electrically connects corresponding pairs of second terminals ofthose first and second packages in each oppositely-mounted package pair.As used herein, when the signal assignments of terminals have “modulo-Xsymmetry” about an axis, terminals that carry signals that have the samenumber “modulo-X” are disposed at positions that are symmetric about theaxis. Thus, in such assembly 300 such as in FIG. 7B, modulo-X symmetrycan permit electrical connections to be made through the circuit panelso that a terminal DQ0 of a first package can be electrically connectedthrough the circuit panel to a terminal DQ8 of the second package thathas the same index number modulo X (X being 8 in this case), so that theconnection can be made in a direction essentially straight through,i.e., normal to, the thickness of the circuit panel.

In one example, “X” can be a number 2^(n) (2 to the power of n), whereinn is greater than or equal to 2, or X can be 8×N, N being two or more.Thus, in one example, X may be equal to the number of bits in ahalf-byte (4 bits), byte (8 bits), multiple bytes (8×N, N being two ormore), a word (32 bits) or multiple words. In such way, in one example,when there is modulo-8 symmetry as shown in FIG. 16B, the signalassignment of a package terminal DQ0 in grid 1274 configured to carrydata signal DQ0 is symmetric about the vertical axis 1251 with thesignal assignment of another package terminal configured to carry datasignal DQ8. Moreover, the same is true for the signal assignments ofpackage terminals DQ0 and DQ8 in grid 1276. As further seen in FIG. 16B,the signal assignments of package terminals DQ2 and DQ10 in grid 1274have modulo-8 symmetry about the vertical axis, and the same is alsotrue for grid 1276. Modulo-8 symmetry such as described herein can beseen in grids 1274, 1276 with respect to each of the signal assignmentsof package terminals DQ0 through DQ15.

It is important to note that, although not shown, the modulo number “X”can be a number other than 2^(n) (2 to the power of n) and can be anynumber greater than two. Thus, the modulo number X upon which thesymmetry is based can depend upon how many bits are present in a datasize for which the package is constructed or configured. For example,when the data size is 10 bits instead of 8, then the signal assignmentsmay have modulo-10 symmetry. It may even be the case that when the datasize has an odd number of bits, the modulo number X can have suchnumber.

FIGS. 17A and 17B illustrate a microelectronic package 1300 according toa variation of the embodiment 1200 described above relative to FIGS. 16Aand 16B, the package 1300 having a substrate surface 1310 having acentral region 1312 in which first terminals 1304 are disposed. As seentherein, microelectronic elements 1330, 1331 are arranged on substrate1302 in a manner similar to the arrangement of microelectronic elements1130, 1131 of microelectronic package 1100 (FIGS. 14A-B, 15), in thatedges 1360 of adjacent microelectronic elements 1130, 1131 are parallelto each other and extend in the same first direction 1342. Edges 1362 ofmicroelectronic elements extend in a direction 1344 transverse to, andtypically orthogonal to the direction 1342.

In some cases, the first edges 1360 of a respective microelectronicelement can have greater length than the second edges 1362 of suchmicroelectronic element. However, in other cases, the second edges 1362can have greater length than the first edges 1360. In the particularpackage seen in FIG. 17A, a plane 1370 that contains either first edge1360 of any of the microelectronic elements 1330, 1331, 1332, or 1333and which is normal to the face of such microelectronic elementintersects the edge 1360 of another microelectronic element within thepackage 1300. For example, as shown in FIG. 17A, the plane 1370 thatcontains the edge 1360 of microelectronic element 1333 extends indirection 1344 and intersects the edge 1360 of microelectronic element1330 within the package. In a particular embodiment, planes 1370A and1370B that contain the first edges of microelectronic element 1333intersect the first edge of no more than one other microelectronicelement within the package. Thus, plane 1370A intersects edges 1360 ofonly microelectronic element 1330.

In addition, as further seen in FIG. 17A, the central region 1312 can befurther limited. Specifically, FIG. 17A shows that there is arectangular subsection area 1372 on the surface 1302 of the substrate1302, beyond which none of the faces of the first, second, third andfourth microelectronic elements 1330, 1331, 1332 and 1333 extend. In themicroelectronic package 1300 depicted in FIGS. 17A-17B, the centralregion 1312 does not extend beyond the boundaries of such rectangularsubsection area 1372.

FIG. 17B further illustrates a possible arrangement of terminals withinmicroelectronic package 1300 in which first terminals 1304 are disposedwithin the central region 1312 which spans a width 1354 in a directionorthogonal to opposed edges 1316, 1318 of the package that is no greaterthan three and one-half times the minimum pitch between the closest twoadjacent columns of terminals on the package. Peripheral regions take upthe remaining area of the surface 1310 of the substrate 1302, spanningwidths 1356, 1357 between edges of the central region and the opposededges 1316, 1318 of the package, respectively.

The microelectronic packages and microelectronic assemblies describedabove with reference to FIGS. 5 through 17B can be utilized inconstruction of diverse electronic systems, such as the system 1500shown in FIG. 18. For example, the system 1500 in accordance with afurther embodiment of the invention includes a plurality of modules orcomponents 1506 such as the microelectronic packages and/ormicroelectronic assemblies as described above in conjunction with otherelectronic components 1508 and 1510.

In the exemplary system 1500 shown, the system can include a circuitpanel, motherboard, or riser panel 1502 such as a flexible printedcircuit board, and the circuit panel can include numerous conductors1504, of which only one is depicted in FIG. 18, interconnecting themodules or components 1506 with one another. Such a circuit panel 1502can transport signals to and from each of the microelectronic packagesand/or microelectronic assemblies included in the system 1500. However,this is merely exemplary; any suitable structure for making electricalconnections between the modules or components 1506 can be used.

In a particular embodiment, the system 1500 can also include a processorsuch as the semiconductor chip 1508, such that each module or component1506 can be configured to transfer a number N of data bits in parallelin a clock cycle, and the processor can be configured to transfer anumber M of data bits in parallel in a clock cycle, M being greater thanor equal to N.

In one example, the system 1500 can include a processor chip 1508 thatis configured to transfer thirty-two data bits in parallel in a clockcycle, and the system can also include four modules 1506 such as themicroelectronic package 100 described with reference to FIG. 5, eachmodule 1506 configured to transfer eight data bits in parallel in aclock cycle (i.e., each module 1506 can include first and secondmicroelectronic elements, each of the two microelectronic elements beingconfigured to transfer four data bits in parallel in a clock cycle).

In another example, the system 1500 can include a processor chip 1508that is configured to transfer sixty-four data bits in parallel in aclock cycle, and the system can also include four modules 1506 such asthe microelectronic package 1200 described with reference to FIGS.16A-B, each module 1506 configured to transfer sixteen data bits inparallel in a clock cycle (i.e., each module 1506 can include fourmicroelectronic elements, each of the four microelectronic elementsbeing configured to transfer four data bits in parallel in a clockcycle).

In the example depicted in FIG. 18, the component 1508 is asemiconductor chip and component 1510 is a display screen, but any othercomponents can be used in the system 1500. Of course, although only twoadditional components 1508 and 1510 are depicted in FIG. 18 for clarityof illustration, the system 1500 can include any number of suchcomponents.

Modules or components 1506 and components 1508 and 1510 can be mountedin a common housing 1501, schematically depicted in broken lines, andcan be electrically interconnected with one another as necessary to formthe desired circuit. The housing 1501 is depicted as a portable housingof the type usable, for example, in a cellular telephone or personaldigital assistant, and screen 1510 can be exposed at the surface of thehousing. In embodiments where a structure 1506 includes alight-sensitive element such as an imaging chip, a lens 1511 or otheroptical device also can be provided for routing light to the structure.Again, the simplified system shown in FIG. 18 is merely exemplary; othersystems, including systems commonly regarded as fixed structures, suchas desktop computers, routers and the like can be made using thestructures discussed above.

The microelectronic packages and microelectronic assemblies describedabove with reference to FIGS. 5-17B can also be utilized in constructionof an electronic system such as the system 1600 shown in FIG. 19. Forexample, the system 1600 in accordance with a further embodiment of theinvention is the same as the system 1500 shown in FIG. 18, except thecomponent 1506 has been replaced by a plurality of components 1606.

Each of the components 1606 can be or can include one or more of themicroelectronic packages or microelectronic assemblies described abovewith reference to FIGS. 5-17B. In a particular example, one or more ofthe components 1606 can be a variation of the microelectronic assembly300 shown in FIG. 7B, in which the circuit panel 354 includes exposededge contacts, and the circuit panel 354 of each microelectronicassembly 300 can be suitable for insertion into a socket 1605.

Each socket 1605 can include a plurality of contacts 1607 at one or bothsides of the socket, such that each socket 1605 can be suitable formating with corresponding exposed edge contacts of a correspondingcomponent 1606 such as the above-described variation of themicroelectronic assembly 300. In the exemplary system 1600 shown, thesystem can include a second circuit panel 1602 or motherboard such as aflexible printed circuit board, and the second circuit panel can includenumerous conductors 1604, of which only one is depicted in FIG. 19,interconnecting the components 1606 with one another.

In a particular example, a module such as the system 1600 can include aplurality of components 1606, each component 1606 being theabove-described variation of the microelectronic assembly 300. Eachcomponent 1606 can be mounted to, and electrically connected with thesecond circuit panel 1602 for transport of signals to and from eachcomponent 1606. The specific example of the system 1600 is merelyexemplary; any suitable structure for making electrical connectionsbetween the components 1606 can be used.

Various features of the above-described embodiments of the invention canbe combined in ways other than as specifically described above withoutdeparting from the scope or spirit of the invention. It is intended forthe present disclosure to cover all such combinations and variations ofembodiments of the invention described above.

It will be appreciated that the various dependent claims and thefeatures set forth therein can be combined in different ways thanpresented in the initial claims. It will also be appreciated that thefeatures described in connection with individual embodiments may beshared with others of the described embodiments.

The invention claimed is:
 1. A microelectronic package, comprising: asubstrate having first and second opposed surfaces and pluralities offirst, second, third, and fourth substrate contacts exposed at the firstsurface, the first and second surfaces each extending in a firstdirection and in a second direction transverse to the first direction;first, second, third, and fourth microelectronic elements each havingmemory storage array function, each microelectronic element having arear face facing the first surface, a front face opposite the firstsurface, parallel first edges each extending in the first direction andbetween the front and rear faces, and parallel second edges eachextending in the second direction and between the front and rear faces,each microelectronic element having element contacts exposed at therespective front face and arranged in one or more columns, each columnextending in the first direction along the respective front face;conductive structure extending above the front faces electricallyconnecting the element contacts of the first, second, third, and fourthmicroelectronic elements with the first, second, third, and fourthsubstrate contacts, respectively; and a plurality of terminals exposedat the second surface and electrically connected with the substratecontacts, the plurality of terminals including first and second groupsof data terminals, each of the first and second groups having at leasteight data terminals disposed on first and second opposite sides of anaxis, respectively, each of the data terminals of the first and secondgroups being configured to carry data signals for read and write accessto random access addressable memory locations of a memory storage arraywithin one or more of the microelectronic elements, and the dataterminals of the first group having modulo X symmetry about the axiswith the second group of the data terminals, X being an integer greaterthan two, wherein the first, second, third, and fourth microelectronicelements are arranged in a vertical stack on the first surface.
 2. Themicroelectronic package as claimed in claim 1, wherein the conductivestructure includes wire bonds extending from the element contacts andelectrically connected with the first, second, third, and fourthsubstrate contacts.
 3. The microelectronic package as claimed in claim1, wherein the conductive structure includes wire bonds extending fromthe element contacts of the first, second, third, and fourthmicroelectronic elements and electrically connected with the respectivefirst, second, third, and fourth substrate contacts.
 4. Themicroelectronic package as claimed in claim 1, wherein each of themicroelectronic elements comprises a lower microelectronic element and acorresponding upper microelectronic element, a rear face of each of theupper microelectronic elements at least partially overlying a front faceof the corresponding lower microelectronic element.
 5. Themicroelectronic package as claimed in claim 1, wherein each column ofelement contacts of each of the microelectronic elements is disposedadjacent one of the first edges of the respective microelectronicelement.
 6. The microelectronic package as claimed in claim 1, whereinthe one or more columns of element contacts of each of themicroelectronic elements is a first column of contacts of the respectivemicroelectronic element, each of the microelectronic elements furtherincludes a second column of contacts exposed at the front face, and thefirst and second columns of contacts of each of the microelectronicelements are disposed adjacent opposite ones of the first edges of therespective microelectronic element.
 7. The microelectronic package asclaimed in claim 1, wherein the one or more columns of element contactsof each of the microelectronic elements is a first column of contacts ofthe respective microelectronic element, each of the microelectronicelements further includes a second column of contacts exposed at thefront face and disposed adjacent one of the second edges of therespective microelectronic element.
 8. The microelectronic package asclaimed in claim 1, wherein the element contacts of each of themicroelectronic elements include redistribution contacts exposed at thefront face of the respective microelectronic element, eachredistribution contact being electrically connected with a contact padof the respective microelectronic element through at least one of atrace or a via, at least some of the redistribution contacts beingdisplaced from the contact pads of the respective microelectronicelement in at least one of the first and second directions along thefront face of the microelectronic element.
 9. The microelectronicpackage as claimed in claim 1, wherein each of the microelectronicelements embodies a greater number of active devices to provide memorystorage array function than any other function.
 10. The microelectronicpackage as claimed in claim 1, wherein the plurality of terminals isconfigured to connect the microelectronic package to at least onecomponent external to the microelectronic package.
 11. Themicroelectronic package as claimed in claim 1, wherein X is equal to 2raised to the power of n, n being greater than or equal to
 2. 12. Themicroelectronic package as claimed in claim 1, wherein X is equal to Ntimes 8, wherein N is a whole number greater than or equal to one. 13.The microelectronic package as claimed in claim 1, further comprisingdata strobe terminals provided on the first and second sides of theaxis, respectively, wherein the signal class assignment of the datastrobe terminal on the first side of the axis is symmetric about theaxis with the signal class assignment of the data strobe terminal on thesecond side of the axis.
 14. The microelectronic package as claimed inclaim 1, further comprising data mask terminals provided on the firstand second sides of the axis, respectively, wherein the signal classassignment of the data mask terminal on the first side of the axis issymmetric about the axis with the signal class assignment of the datamask terminal on the second side of the axis.
 15. The microelectronicpackage as claimed in claim 1, wherein the terminals further includeother terminals disposed between the first and second groups of dataterminals that are configured to carry signals other than the signalscarried by the data terminals.
 16. The microelectronic package asclaimed in claim 15, wherein the other terminals disposed between thefirst and second groups of data terminals are configured to carryaddress information usable by circuitry within the microelectronicpackage to determine an addressable memory location from among all theavailable addressable memory locations of the memory storage array. 17.The microelectronic package as claimed in claim 16, wherein the otherterminals disposed between the first and second groups of data terminalsare configured to carry all of the address information usable by thecircuitry within the microelectronic package to determine theaddressable memory location.
 18. A system comprising a microelectronicpackage and one or more other electronic components electricallyconnected to the microelectronic package, the microelectronic packagecomprising: a substrate having first and second opposed surfaces andpluralities of first, second, third, and fourth substrate contactsexposed at the first surface, the first and second surfaces eachextending in a first direction and in a second direction transverse tothe first direction; first, second, third, and fourth microelectronicelements each having memory storage array function, each microelectronicelement having a rear face facing the first surface, a front faceopposite the first surface, parallel first edges each extending in thefirst direction and between the front and rear faces, and parallelsecond edges each extending in the second direction and between thefront and rear faces, each microelectronic element having elementcontacts exposed at the respective front face and arranged in one ormore columns, each column extending in the first direction along therespective front face; conductive structure extending above the frontfaces electrically connecting the element contacts of the first, second,third, and fourth microelectronic elements with the first, second,third, and fourth substrate contacts, respectively; and a plurality ofterminals exposed at the second surface and electrically connected withthe substrate contacts, the plurality of terminals including first andsecond groups of data terminals, each of the first and second groupshaving at least eight data terminals disposed on first and secondopposite sides of an axis, respectively, each of the data terminals ofthe first and second groups being configured to carry data signals forread and write access to random access addressable memory locations of amemory storage array within one or more of the microelectronic elements,and the data terminals of the first group having modulo X symmetry aboutthe axis with the second group of the data terminals, X being an integergreater than two, wherein the first, second, third, and fourthmicroelectronic elements are arranged in a vertical stack on the firstsurface.
 19. The system as claimed in claim 18, further comprising ahousing, the microelectronic package and the one or more otherelectronic components being assembled with the housing.